fix: audit phase 2 — teardown, failure paths, service worker, tooltip, resize

Correctness phase of the frontend audit. Nothing here is visible on a happy
path; it is what the app does when something goes wrong, when the window
changes, or when the component goes away.

Teardown (new src/lib/pixi/lifecycle.ts):
- Nothing was ever released: no app.destroy(), no ticker.remove(), no
  killTweensOf, no onDestroy. ~480 GSAP tweens (most repeat:-1), a ticker
  callback, and a dozen DOM listeners lived forever.
- 112 of those tweens are created inside an onComplete, so they don't exist
  when a call-site sweep would run. gsap.context() handles exactly this:
  GSAP records each animation's context on creation and restores it while
  invoking that animation's callbacks (see _callback in gsap-core), so
  late-created pulses land in the same context. One ctx.kill() gets all of
  them. kill(), not revert(), so GSAP doesn't write properties back onto
  objects about to be destroyed.
- All DOM listeners now go through life.listen(), which registers removal at
  the same time. Previously 6 canvas listeners were never removed, each
  closing over the whole ~713-object scene graph.
- The unmount race: cleanup used to be registered on the LAST line of an
  async onMount, after the asset waterfall, so unmounting mid-load cleaned up
  nothing. The lifecycle is now created before any await, with life.disposed
  guards after each one.
- Hover tweens re-enter the context per event and use overwrite:'auto' so
  rapid sweeps don't stack conflicting tweens.

Failure paths:
- onMount had no try/catch and no WebGL detection. Any init or asset failure
  left the spinner up forever, the stats toggle at opacity:0, and Escape dead
  (attachKeyboard never ran). Now caught, and it hands off to +page.svelte to
  reveal the text version.
- There was no <noscript> anywhere, and SeoContent is clipped to 1x1px with
  html/body overflow:hidden — so JS-disabled visitors got a pure black page.
  A <noscript><style> block now un-hides it with no JS involved.

Service worker (moved static/ -> src/, so SvelteKit builds it):
- It can now use $service-worker, so precache comes from the real build
  manifest instead of a hand-maintained 5-entry list that omitted all JS/CSS,
  and the cache name embeds `version` so old caches actually get pruned.
- cache.addAll was atomic: one 404 failed the whole install silently. Now
  per-asset with a warning on partial failure.
- The catch returned undefined for non-image assets, which makes
  respondWith throw a TypeError — a soft offline failure became a hard one.
  Every path now resolves to a Response.
- Unhashed assets (icons, headshot, resume PDF) were cache-first with no
  expiry, so replacing the resume at the same URL never reached a returning
  visitor. Those are network-first now; only hashed build output is
  cache-first.
- Navigation responses were cached without a status check, so a 404/500 body
  could become the offline fallback.
- Dropped skipWaiting() from install and added a real update prompt +
  controllerchange reload. The SKIP_WAITING handler was previously dead code
  and the "check for updates periodically" comment described an interval that
  did not exist.

Tooltip:
- Wrote Svelte state on every canvas mousemove even with nothing hovered.
  Now gated on hover and coalesced to one write per frame; raw coords are
  still tracked cheaply so the first hover isn't positioned from stale data.
- Animated left/top (layout + paint per frame on an element with two
  color-mix shadows); now translate3d.
- Listener moved to window, so coordinates no longer freeze when a drag
  leaves the canvas.
- Flip logic measured a hardcoded 280x120; now measures the real element
  (actual height is 113, so tall tooltips mis-flipped near the bottom edge).
- Dropped role="tooltip" + aria-live="polite", which announced the full
  label and description on every hover. Nothing referenced it via
  aria-describedby, so the role was inert. Now aria-hidden.

Resize:
- Star positions, gradient radius, vignette size and dust wrap bounds were
  all baked at first paint, so enlarging the window left an unlit band. The
  background is now rebuilt on a rAF-coalesced resize, under its own
  sub-lifecycle. The view is shifted by half the delta rather than re-centred,
  so the user's current view stays anchored.
- isTouchDevice used 'ontouchstart', true on touch-capable laptops and thus
  permanently killing mouse hover. Now matchMedia('(hover: hover)').

Known gap: node radii still don't change when the 768px breakpoint is
crossed mid-session; re-creating all 57 nodes would reset interaction state.

Verified in the production build: resize 1278x1220 -> 1734x821 rebuilds with
zero errors, tooltip positions via transform and stays on screen, fallback
renders as a readable resume page. svelte-check clean, lint clean, 14/14.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

src/app.css

@@ -47,3 +47,43 @@ body {
 	white-space: nowrap;
 	border: 0;
 }
+
+/*
+ * Un-hides the text version when the canvas can't run — no JS, or no WebGL.
+ * Applied by <noscript> (see +layout.svelte) and by the render-failure path in
+ * SkillTree.svelte. Also restores scrolling, which is disabled globally above
+ * for the canvas view.
+ */
+.sr-only.revealed {
+	position: static;
+	width: auto;
+	height: auto;
+	margin: 0;
+	overflow: visible;
+	clip: auto;
+	white-space: normal;
+	max-width: 60rem;
+	padding: 2rem 1.5rem;
+	color: #e8e8f0;
+	line-height: 1.6;
+}
+
+html:has(.sr-only.revealed),
+html:has(.sr-only.revealed) body {
+	overflow: auto;
+}
+
+.sr-only.revealed a {
+	color: var(--color-gold);
+}
+
+.sr-only.revealed h1,
+.sr-only.revealed h2,
+.sr-only.revealed h3 {
+	color: var(--color-gold);
+	margin: 1.25rem 0 0.5rem;
+}
+
+.sr-only.revealed ul {
+	padding-left: 1.25rem;
+}

src/lib/components/SeoContent.svelte

@@ -14,6 +14,10 @@
 	} from '$lib/data';
 	import { aggregateSkills, BRANCH_IDS } from '$lib/utils/stats';
 
+	// Set when the canvas can't render, so this becomes the visible page rather
+	// than a screen-reader-only mirror of it.
+	const { revealed = false }: { revealed?: boolean } = $props();
+
 	const origin = treeNodes.find((n): n is OriginNode => n.category === 'origin');
 
 	// Leaf nodes only — container/branch nodes lack these category fields.
@@ -34,7 +38,7 @@
 </script>
 
 {#if origin}
-	<section class="sr-only" aria-label="Portfolio (text version)">
+	<section class="sr-only" class:revealed aria-label="Portfolio (text version)">
 		<h1>{origin.fullName} — {origin.jobTitle}</h1>
 		{#if origin.aboutMe}<p>{origin.aboutMe}</p>{/if}
 		{#if origin.location}<p>Location: {origin.location}</p>{/if}

src/lib/components/SkillTree.svelte

@@ -21,8 +21,11 @@
 	import { createController } from '$lib/pixi/controller';
 	import { createLines } from '$lib/pixi/lines';
 	import { createNodes } from '$lib/pixi/nodes';
-	import { attachPanZoom, attachKeyboard } from '$lib/pixi/interaction';
+	import { attachPanZoom, attachKeyboard, updateParallax } from '$lib/pixi/interaction';
 	import { runEntranceAnimations } from '$lib/pixi/animation';
+	import { createLifecycle } from '$lib/pixi/lifecycle';
+
+	const { onRenderFail }: { onRenderFail?: () => void } = $props();
 
 	let container: HTMLDivElement;
 	let selectedNode = $state<TreeNode | null>(null);
@@ -48,7 +51,7 @@
 	let statsPanelVisible = $state(false);
 	// SvelteSet, not $state(new Set()) — Svelte 5 does not proxy a plain Set, so
 	// .add()/.delete() would be untracked and the panel would never re-render.
-	let expandedBranches = new SvelteSet<string>(BRANCH_IDS); // All expanded by default
+	const expandedBranches = new SvelteSet<string>(BRANCH_IDS); // All expanded by default
 
 	function openModal(node: TreeNode) {
 		selectedNode = node;
@@ -100,15 +103,23 @@
 		isMobile = windowWidth < MOBILE_BREAKPOINT;
 	}
 
-	const cleanupFunctions: Array<() => void> = [];
+	// One owner for every Pixi/GSAP/DOM resource this component allocates.
+	// Registered with the component's teardown BEFORE any await, so unmounting
+	// mid-load still releases everything (this used to be the last statement of
+	// the async onMount, so an early unmount cleaned up nothing at all).
+	const life = createLifecycle();
 
 	onMount(async () => {
 		handleResize();
-		window.addEventListener('resize', handleResize);
+		life.listen(window, 'resize', handleResize);
 
-		const isTouchDevice = 'ontouchstart' in window || navigator.maxTouchPoints > 0;
+		// matchMedia('(hover: hover)') rather than 'ontouchstart': the latter is
+		// true on touch-capable laptops, which permanently killed mouse hover.
+		const isTouchDevice = !window.matchMedia('(hover: hover)').matches;
 
 		const app = new Application();
+
+		try {
 			await app.init({
 				background: '#05050a',
 				resizeTo: container,
@@ -120,12 +131,26 @@
 				powerPreference: 'high-performance'
 			});
 
+			// Unmounted while the renderer was initialising — release and stop.
+			if (life.disposed) {
+				app.destroy(true, { children: true, texture: true });
+				return;
+			}
+
+			// Tearing down the renderer has to happen last, so register it first
+			// (dispose runs newest-first).
+			life.add(() => app.destroy(true, { children: true, texture: true }));
+
 			// PixiJS owns this canvas, not Svelte — mounting it directly is intentional.
 			// eslint-disable-next-line svelte/no-dom-manipulating
 			container.appendChild(app.canvas);
 
-		// Background layers (gradient → nebula → stars → dust → vignette)
-		const bg = createBackground(app, isMobile);
+			// Background layers (gradient → nebula → stars → dust → vignette).
+			// Its own sub-lifecycle so a resize rebuild can kill just its ~315
+			// ambient tweens and the dust ticker, without touching the tree's.
+			let bgLife = createLifecycle();
+			let bg = createBackground(app, isMobile, bgLife);
+			life.add(() => bgLife.dispose());
 
 			// Tree container — pan/zoom transform is applied here
 			const treeContainer = new Container();
@@ -147,71 +172,143 @@
 				isMobile,
 				isTouchDevice,
 				controller,
+				life,
 				onOpen: openModal,
 				onHover: (node) => {
 					hoveredNode = node;
+					// Seed the tooltip at the current pointer before it first paints.
+					if (node) panZoom?.flushTooltip();
 				}
 			});
 
+			// Unmounted while textures were loading.
+			if (life.disposed) return;
+
 			// Textures are loaded and the scene graph is built — only now is the canvas
 			// genuinely ready. (This used to fire right after app.init(), so the spinner
 			// resolved onto an empty screen.)
 			isLoading = false;
 
 			// Pan / zoom / parallax + keyboard navigation
-		const detachPanZoom = attachPanZoom(controller, {
+			const panZoom = attachPanZoom(
+				controller,
+				{
 					onTooltipMove: (x, y) => {
 						tooltipX = x;
 						tooltipY = y;
-			}
-		});
-		const detachKeyboard = attachKeyboard(controller, {
+					},
+					hasHover: () => hoveredNode !== null
+				},
+				life
+			);
+			attachKeyboard(
+				controller,
+				{
 					onToggleStats: toggleStatsPanel,
 					onCloseModal: closeModal,
 					isModalVisible: () => modalVisible,
 					isStatsVisible: () => statsPanelVisible
+				},
+				life
+			);
+
+			// Every star position, the gradient radius, the vignette size and the
+			// dust wrap bounds are baked from app.screen at build time. Without this
+			// a resized window leaves an unlit, starless band.
+			let lastWidth = app.screen.width;
+			let lastHeight = app.screen.height;
+			let resizeFrame = -1;
+
+			function rebuildBackground() {
+				bgLife.dispose();
+				bg.deepBackgroundContainer.destroy({ children: true });
+				bg.nebulaContainer.destroy({ children: true });
+				bg.starContainer.destroy({ children: true });
+				bg.vignette.destroy();
+
+				bgLife = createLifecycle();
+				bg = createBackground(app, isMobile, bgLife);
+				controller.bg = bg;
+
+				// createBackground appends to the stage, so the tree would end up
+				// behind the new layers. Restore it to the top.
+				app.stage.setChildIndex(treeContainer, app.stage.children.length - 1);
+				updateParallax(controller);
+			}
+
+			function handleCanvasResize() {
+				resizeFrame = -1;
+				const width = app.screen.width;
+				const height = app.screen.height;
+				if (width === lastWidth && height === lastHeight) return;
+
+				// Keep whatever the user was looking at anchored: shift by half the
+				// delta rather than snapping back to centre and yanking their view.
+				const dx = (width - lastWidth) / 2;
+				const dy = (height - lastHeight) / 2;
+				treeContainer.x += dx;
+				treeContainer.y += dy;
+				controller.initialTreeX += dx;
+				controller.initialTreeY += dy;
+
+				lastWidth = width;
+				lastHeight = height;
+				rebuildBackground();
+			}
+
+			// Coalesce to one rebuild per frame — resize fires continuously while
+			// dragging a window edge, and a rebuild allocates ~300 Graphics.
+			life.listen(window, 'resize', () => {
+				if (resizeFrame === -1) resizeFrame = requestAnimationFrame(handleCanvasResize);
+			});
+			life.add(() => {
+				if (resizeFrame !== -1) cancelAnimationFrame(resizeFrame);
 			});
 
 			// Sequenced entrance animation
 			runEntranceAnimations(controller, {
 				isMobile,
+				life,
 				onTitleDone: () => {
 					showWelcomeTitle = false;
 				}
 			});
-
-		// Store cleanup functions
-		cleanupFunctions.push(() => {
-			window.removeEventListener('resize', handleResize);
-			detachPanZoom();
-			detachKeyboard();
-		});
+		} catch (err) {
+			// No WebGL, or a texture failed to load. Don't strand the user on a
+			// spinner that never resolves — reveal the text version instead.
+			console.error('Skill tree failed to initialise:', err);
+			isLoading = false;
+			// Hands off to +page.svelte, which reveals the text version.
+			onRenderFail?.();
+			life.dispose();
+			app.destroy(true, { children: true, texture: true });
+		}
 	});
 
 	// Cleanup on component unmount
 	$effect(() => {
-		return () => {
-			cleanupFunctions.forEach((fn) => fn());
-		};
+		return () => life.dispose();
 	});
 
-	// Calculate tooltip position to keep it on screen
+	// Live tooltip element, so flip decisions use its real measured size rather
+	// than a hardcoded 280x120 guess (descriptions vary in length, so the old
+	// height constant mis-flipped tall tooltips near the viewport bottom).
+	let tooltipEl = $state<HTMLDivElement | null>(null);
+
 	const tooltipStyle = $derived.by(() => {
-		let x = tooltipX + 15;
-		let y = tooltipY + 15;
+		const gap = 15;
+		const rect = tooltipEl?.getBoundingClientRect();
+		const width = rect?.width || 280;
+		const height = rect?.height || 120;
 
-		// Keep tooltip on screen
-		const tooltipWidth = 280;
-		const tooltipHeight = 120;
+		let x = tooltipX + gap;
+		let y = tooltipY + gap;
 
-		if (x + tooltipWidth > windowWidth) {
-			x = tooltipX - tooltipWidth - 15;
-		}
-		if (y + tooltipHeight > windowHeight) {
-			y = tooltipY - tooltipHeight - 15;
-		}
+		// Flip to the other side of the cursor rather than overflow the viewport.
+		if (x + width > windowWidth) x = Math.max(0, tooltipX - width - gap);
+		if (y + height > windowHeight) y = Math.max(0, tooltipY - height - gap);
 
-		return `left: ${x}px; top: ${y}px;`;
+		return `transform: translate3d(${x}px, ${y}px, 0);`;
 	});
 </script>
 
@@ -239,6 +336,7 @@
 <!-- Hover Tooltip (hidden on mobile) -->
 {#if hoveredNode && !modalVisible && !isMobile}
 	<Tooltip
+		bind:element={tooltipEl}
 		node={hoveredNode}
 		style={tooltipStyle}
 		colorHex={categoryColorHex[hoveredNode.category]}

src/lib/components/Tooltip.svelte

@@ -1,10 +1,34 @@
 <script lang="ts">
 	import type { TreeNode } from '$lib/data';
 
-	const { node, style, colorHex }: { node: TreeNode; style: string; colorHex: string } = $props();
+	// `let`, not `const`: bind:this assigns to `element`, and a bindable prop is
+	// only writable when destructured with let.
+	let {
+		node,
+		style,
+		colorHex,
+		element = $bindable(null)
+	}: {
+		node: TreeNode;
+		style: string;
+		colorHex: string;
+		element?: HTMLDivElement | null;
+	} = $props();
 </script>
 
-<div class="tooltip" role="tooltip" aria-live="polite" style="{style} --node-color: {colorHex};">
+<!--
+	aria-hidden: this is a mouse-only visual duplicate of canvas content. It used
+	to carry role="tooltip" + aria-live="polite", which announced the full label,
+	description and "Click for details" on every single hover. Nothing references
+	it via aria-describedby either — the trigger is a WebGL sprite with no DOM
+	node — so the role was inert anyway. The accessible path is the text version.
+-->
+<div
+	bind:this={element}
+	class="tooltip"
+	aria-hidden="true"
+	style="{style} --node-color: {colorHex};"
+>
 	<h3>
 		{#if node.icon}
 			<img src={node.icon} alt="" class="tooltip-icon" />
@@ -18,6 +42,12 @@
 <style>
 	.tooltip {
 		position: fixed;
+		/* Positioned via translate3d, not left/top: moving on the compositor
+		   avoids a layout+paint per frame on an element with two color-mix
+		   shadows. The offsets live in the transform, so these stay at 0. */
+		top: 0;
+		left: 0;
+		will-change: transform;
 		background: linear-gradient(145deg, var(--panel-from) 0%, #12121a 100%);
 		border: 1px solid var(--node-color);
 		border-radius: 8px;

src/lib/pixi/animation.ts

@@ -6,9 +6,11 @@ import { gsap } from 'gsap';
 import { getDistanceFromOrigin } from '$lib/utils/tree';
 import { updateParallax } from './interaction';
 import type { SkillTreeController } from './controller';
+import type { Lifecycle } from './lifecycle';
 
 interface EntranceOpts {
 	isMobile: boolean;
+	life: Lifecycle;
 	/** Called when the welcome title should be removed (matches its CSS fade). */
 	onTitleDone: () => void;
 }
@@ -22,6 +24,11 @@ export function runEntranceAnimations(ctrl: SkillTreeController, opts: EntranceO
 	const zoomDuration = isMobile ? 2.5 : 4.5;
 	const nodeStagger = isMobile ? 0.05 : 0.08;
 
+	// The entrance allocates ~340 finite tweens plus ~170 `repeat: -1` pulses,
+	// some created inside an onComplete. GSAP restores an animation's context
+	// while running its callbacks, so wrapping the whole sequence here makes
+	// even those late-created pulses killable via the lifecycle.
+	opts.life.animate(() => {
 		// Hide all lines and plasma beams initially
 		lineObjects.forEach((line) => {
 			line.graphics.alpha = 0;
@@ -202,12 +209,13 @@ export function runEntranceAnimations(ctrl: SkillTreeController, opts: EntranceO
 		});
 
 		// Clean up title card after animation (matches titleDuration)
-	setTimeout(
+		const titleTimer = setTimeout(
 			() => {
 				opts.onTitleDone();
 			},
 			isMobile ? 1500 : 2500
 		);
+		opts.life.add(() => clearTimeout(titleTimer));
 
 		// Fade in stats panel toggle button with the tree
 		const toggleButton = document.querySelector('.stats-panel-toggle');
@@ -219,4 +227,5 @@ export function runEntranceAnimations(ctrl: SkillTreeController, opts: EntranceO
 				ease: 'power2.out'
 			});
 		}
+	});
 }

src/lib/pixi/background.ts

@@ -6,9 +6,15 @@ import { gsap } from 'gsap';
 import { nebulaPalette } from '$lib/theme';
 import { PARTICLE_COUNTS, byDevice } from '$lib/config';
 import type { BackgroundLayers } from './types';
+import type { Lifecycle } from './lifecycle';
 
-export function createBackground(app: Application, isMobile: boolean): BackgroundLayers {
+export function createBackground(
+	app: Application,
+	isMobile: boolean,
+	life: Lifecycle
+): BackgroundLayers {
 	const deepBackgroundContainer = new Container();
+	let vignette!: Graphics;
 	const nebulaContainer = new Container();
 	const starContainer = new Container();
 
@@ -16,6 +22,9 @@ export function createBackground(app: Application, isMobile: boolean): Backgroun
 	app.stage.addChild(nebulaContainer);
 	app.stage.addChild(starContainer);
 
+	// Everything below allocates `repeat: -1` ambient tweens; building it inside
+	// the lifecycle's GSAP context makes all of them killable on teardown.
+	life.animate(() => {
 		const screenWidth = app.screen.width;
 		const screenHeight = app.screen.height;
 		const centerX = screenWidth / 2;
@@ -225,9 +234,10 @@ export function createBackground(app: Application, isMobile: boolean): Backgroun
 			}
 		}
 		app.ticker.add(driftDust);
+		life.add(() => app.ticker.remove(driftDust));
 
 		// ========== VIGNETTE OVERLAY ==========
-	const vignette = new Graphics();
+		vignette = new Graphics();
 		const vignetteSize = Math.max(screenWidth, screenHeight) * 1.2;
 
 		for (let i = 12; i >= 0; i--) {
@@ -248,6 +258,7 @@ export function createBackground(app: Application, isMobile: boolean): Backgroun
 		nebulaContainer.interactiveChildren = false;
 		starContainer.interactiveChildren = false;
 		vignette.eventMode = 'none';
+	});
 
-	return { deepBackgroundContainer, nebulaContainer, starContainer };
+	return { deepBackgroundContainer, nebulaContainer, starContainer, vignette };
 }

src/lib/pixi/interaction.ts

@@ -6,6 +6,7 @@
 import { gsap } from 'gsap';
 import { ZOOM, PARALLAX, PAN_SPEED } from '$lib/config';
 import type { SkillTreeController } from './controller';
+import type { Lifecycle } from './lifecycle';
 
 /** Offset the background layers behind the tree to create parallax depth. */
 export function updateParallax(ctrl: SkillTreeController) {
@@ -25,16 +26,31 @@ export function updateParallax(ctrl: SkillTreeController) {
 
 interface PanZoomOpts {
 	onTooltipMove: (x: number, y: number) => void;
+	/** Tooltip coords are only worth computing while a node is actually hovered. */
+	hasHover: () => boolean;
 }
 
-/** Wire mouse/touch/wheel pan + zoom. Returns a cleanup for window listeners. */
-export function attachPanZoom(ctrl: SkillTreeController, opts: PanZoomOpts): () => void {
+export interface PanZoomHandle {
+	/**
+	 * Push the current pointer position to the tooltip immediately. Needed on
+	 * hover-start: the move handler below only writes state while a node is
+	 * hovered, so without this the first hover would render at stale coords.
+	 */
+	flushTooltip: () => void;
+}
+
+/** Wire mouse/touch/wheel pan + zoom. Every listener is owned by `life`. */
+export function attachPanZoom(
+	ctrl: SkillTreeController,
+	opts: PanZoomOpts,
+	life: Lifecycle
+): PanZoomHandle {
 	const { app, treeContainer } = ctrl;
 	const minZoom = ZOOM.min;
 	const maxZoom = ZOOM.max;
 
 	// ===== MOUSE PANNING =====
-	app.canvas.addEventListener('mousedown', (e: MouseEvent) => {
+	life.listen(app.canvas, 'mousedown', (e: MouseEvent) => {
 		ctrl.isDragging = true;
 		ctrl.hasMoved = false;
 		ctrl.dragStartX = e.clientX;
@@ -55,23 +71,47 @@ export function attachPanZoom(ctrl: SkillTreeController, opts: PanZoomOpts): ()
 		treeContainer.y = ctrl.containerStartY + dy;
 		updateParallax(ctrl);
 	};
-	window.addEventListener('mousemove', onWindowMouseMove);
+	life.listen(window, 'mousemove', onWindowMouseMove);
 
 	const onWindowMouseUp = () => {
 		ctrl.isDragging = false;
 		app.canvas.style.cursor = 'grab';
 	};
-	window.addEventListener('mouseup', onWindowMouseUp);
+	life.listen(window, 'mouseup', onWindowMouseUp);
 
 	app.canvas.style.cursor = 'grab';
 
-	// Track mouse position for tooltip
-	app.canvas.addEventListener('mousemove', (e: MouseEvent) => {
-		opts.onTooltipMove(e.clientX, e.clientY);
+	// Track mouse position for the tooltip.
+	//
+	// Three things matter here. It is gated on `hasHover()` so moving the mouse
+	// across empty canvas costs nothing (this previously wrote Svelte state on
+	// every single mousemove, hovered or not). It coalesces to one write per
+	// frame instead of one per pointer event. And it listens on `window`, not the
+	// canvas, so coordinates keep updating when a drag leaves the canvas bounds.
+	let tooltipFrame = -1;
+	let tooltipPointerX = 0;
+	let tooltipPointerY = 0;
+
+	const flushTooltip = () => {
+		tooltipFrame = -1;
+		opts.onTooltipMove(tooltipPointerX, tooltipPointerY);
+	};
+
+	life.listen(window, 'mousemove', (e: MouseEvent) => {
+		// Raw coords are always tracked — two plain number writes, negligible.
+		// What was expensive, and is now gated, is writing Svelte state.
+		tooltipPointerX = e.clientX;
+		tooltipPointerY = e.clientY;
+		if (!opts.hasHover()) return;
+		if (tooltipFrame === -1) tooltipFrame = requestAnimationFrame(flushTooltip);
+	});
+	life.add(() => {
+		if (tooltipFrame !== -1) cancelAnimationFrame(tooltipFrame);
 	});
 
 	// ===== TOUCH PANNING & PINCH ZOOM =====
-	app.canvas.addEventListener(
+	life.listen(
+		app.canvas,
 		'touchstart',
 		(e: TouchEvent) => {
 			if (e.touches.length === 1) {
@@ -94,7 +134,8 @@ export function attachPanZoom(ctrl: SkillTreeController, opts: PanZoomOpts): ()
 		{ passive: true }
 	);
 
-	app.canvas.addEventListener(
+	life.listen(
+		app.canvas,
 		'touchmove',
 		(e: TouchEvent) => {
 			if (e.touches.length === 1 && ctrl.isDragging && !ctrl.isTouchZooming) {
@@ -129,7 +170,8 @@ export function attachPanZoom(ctrl: SkillTreeController, opts: PanZoomOpts): ()
 		{ passive: true }
 	);
 
-	app.canvas.addEventListener(
+	life.listen(
+		app.canvas,
 		'touchend',
 		(e: TouchEvent) => {
 			if (e.touches.length === 0) {
@@ -150,7 +192,12 @@ export function attachPanZoom(ctrl: SkillTreeController, opts: PanZoomOpts): ()
 	);
 
 	// ===== WHEEL ZOOM =====
-	app.canvas.addEventListener('wheel', (e: WheelEvent) => {
+	// Explicitly non-passive: this calls preventDefault(). It works by default on
+	// a non-root element, but relying on that is an implicit dependency.
+	life.listen(
+		app.canvas,
+		'wheel',
+		(e: WheelEvent) => {
 			e.preventDefault();
 			const oldScale = treeContainer.scale.x;
 			const zoomFactor = e.deltaY > 0 ? ZOOM.wheelOut : ZOOM.wheelIn;
@@ -160,12 +207,11 @@ export function attachPanZoom(ctrl: SkillTreeController, opts: PanZoomOpts): ()
 			// (treeContainer.x, treeContainer.y), so scaling keeps it anchored.
 			treeContainer.scale.set(newScale);
 			updateParallax(ctrl);
-	});
+		},
+		{ passive: false }
+	);
 
-	return () => {
-		window.removeEventListener('mousemove', onWindowMouseMove);
-		window.removeEventListener('mouseup', onWindowMouseUp);
-	};
+	return { flushTooltip };
 }
 
 interface KeyboardOpts {
@@ -175,8 +221,8 @@ interface KeyboardOpts {
 	isStatsVisible: () => boolean;
 }
 
-/** Wire keyboard navigation (pan/zoom/reset/stats/escape). Returns cleanup. */
-export function attachKeyboard(ctrl: SkillTreeController, opts: KeyboardOpts): () => void {
+/** Wire keyboard navigation (pan/zoom/reset/stats/escape). Owned by `life`. */
+export function attachKeyboard(ctrl: SkillTreeController, opts: KeyboardOpts, life: Lifecycle) {
 	const { app, treeContainer } = ctrl;
 	const minZoom = ZOOM.min;
 	const maxZoom = ZOOM.max;
@@ -241,11 +287,14 @@ export function attachKeyboard(ctrl: SkillTreeController, opts: KeyboardOpts): (
 		// R to reset view to origin
 		if (e.key === 'r' || e.key === 'R') {
 			e.preventDefault();
+			// Re-enter the GSAP context: these are created per keypress.
+			life.animate(() => {
 				gsap.to(treeContainer, {
 					x: app.screen.width / 2,
 					y: app.screen.height / 2,
 					duration: 0.5,
 					ease: 'power2.out',
+					overwrite: 'auto',
 					onUpdate: () => updateParallax(ctrl),
 					onComplete: () => {
 						// Update parallax baseline after reset
@@ -258,11 +307,12 @@ export function attachKeyboard(ctrl: SkillTreeController, opts: KeyboardOpts): (
 					y: ctrl.endScale,
 					duration: 0.5,
 					ease: 'power2.out',
+					overwrite: 'auto',
 					onUpdate: () => updateParallax(ctrl)
 				});
+			});
 		}
 	}
 
-	window.addEventListener('keydown', handleKeydown);
-	return () => window.removeEventListener('keydown', handleKeydown);
+	life.listen(window, 'keydown', handleKeydown);
 }

src/lib/pixi/lifecycle.ts

@@ -0,0 +1,74 @@
+// Single owner for every resource the tree allocates, so one dispose() call
+// releases all of it.
+//
+// Why this exists: the PixiJS layer creates ~480 infinite GSAP tweens, a ticker
+// callback, and a dozen DOM listeners. None of them were ever released, and 112
+// of the tweens are created inside an `onComplete` — so they don't exist yet at
+// the moment a naive `killTweensOf` sweep would run.
+//
+// `gsap.context()` solves exactly that: GSAP records each animation's context on
+// creation, and restores that context while invoking the animation's callbacks
+// (see `_callback` in gsap-core). So a tween created inside a tracked tween's
+// onComplete is tracked by the same context, and ctx.kill() gets all of them.
+import { gsap } from 'gsap';
+
+export function createLifecycle() {
+	const disposers: Array<() => void> = [];
+	const gsapCtx = gsap.context(() => {});
+	let isDisposed = false;
+
+	return {
+		/** True once dispose() has run — guards async work that resolves late. */
+		get disposed() {
+			return isDisposed;
+		},
+
+		/**
+		 * Run `fn` with GSAP's active context set, so every tween it creates is
+		 * tracked for teardown. Returns whatever `fn` returns.
+		 */
+		animate<T>(fn: () => T): T {
+			return gsapCtx.add(fn) as T;
+		},
+
+		/** Register an arbitrary teardown step. */
+		add(fn: () => void) {
+			disposers.push(fn);
+		},
+
+		/** Add a DOM listener and register its removal in one call. */
+		listen<T extends EventTarget>(
+			target: T,
+			type: string,
+			handler: (event: never) => void,
+			options?: AddEventListenerOptions
+		) {
+			target.addEventListener(type, handler as EventListener, options);
+			disposers.push(() => target.removeEventListener(type, handler as EventListener, options));
+		},
+
+		/**
+		 * Release everything, newest first. `kill()` rather than `revert()`: we do
+		 * not want GSAP writing properties back onto Pixi objects that are about
+		 * to be destroyed.
+		 */
+		dispose() {
+			if (isDisposed) return;
+			isDisposed = true;
+
+			gsapCtx.kill();
+
+			for (let i = disposers.length - 1; i >= 0; i--) {
+				try {
+					disposers[i]();
+				} catch (err) {
+					// One failing teardown step must not strand the rest.
+					console.warn('Teardown step failed:', err);
+				}
+			}
+			disposers.length = 0;
+		}
+	};
+}
+
+export type Lifecycle = ReturnType<typeof createLifecycle>;

src/lib/pixi/nodes.ts

@@ -8,11 +8,13 @@ import { categoryColors } from '$lib/theme';
 import { getNodeRadius } from '$lib/utils/tree';
 import type { NodeObject } from './types';
 import type { SkillTreeController } from './controller';
+import type { Lifecycle } from './lifecycle';
 
 interface NodeOpts {
 	isMobile: boolean;
 	isTouchDevice: boolean;
 	controller: SkillTreeController;
+	life: Lifecycle;
 	onOpen: (node: TreeNode) => void;
 	onHover: (node: TreeNode | null) => void;
 }
@@ -34,15 +36,22 @@ function attachNodeInteraction(
 		}
 	});
 
+	// Hover tweens are created per-event, long after setup, so each creation has
+	// to re-enter the GSAP context to stay killable. `overwrite: 'auto'` stops
+	// rapid in/out sweeps from stacking conflicting tweens on the same property.
 	target.on('pointerover', () => {
-		gsap.to(target.scale, { x: 1.2, y: 1.2, duration: 0.2 });
-		gsap.to(glowGraphics, { alpha: 1.5, duration: 0.2 });
+		opts.life.animate(() => {
+			gsap.to(target.scale, { x: 1.2, y: 1.2, duration: 0.2, overwrite: 'auto' });
+			gsap.to(glowGraphics, { alpha: 1.5, duration: 0.2, overwrite: 'auto' });
+		});
 		if (!opts.isTouchDevice) opts.onHover(node);
 	});
 
 	target.on('pointerout', () => {
-		gsap.to(target.scale, { x: 1, y: 1, duration: 0.2 });
-		gsap.to(glowGraphics, { alpha: 1, duration: 0.2 });
+		opts.life.animate(() => {
+			gsap.to(target.scale, { x: 1, y: 1, duration: 0.2, overwrite: 'auto' });
+			gsap.to(glowGraphics, { alpha: 1, duration: 0.2, overwrite: 'auto' });
+		});
 		if (!opts.isTouchDevice) opts.onHover(null);
 	});
 }
@@ -59,7 +68,9 @@ export async function createNodes(treeContainer: Container, opts: NodeOpts): Pro
 	const [profileTexture, iconTextures] = await Promise.all([
 		Assets.load<Texture>('/headshot.jpg'),
 		// Array form resolves to a url -> Texture map and fetches concurrently.
-		iconUrls.length ? Assets.load<Texture>(iconUrls) : Promise.resolve({} as Record<string, Texture>)
+		iconUrls.length
+			? Assets.load<Texture>(iconUrls)
+			: Promise.resolve({} as Record<string, Texture>)
 	]);
 
 	for (const node of treeNodes) {

src/lib/pixi/types.ts

@@ -19,9 +19,11 @@ export interface NodeObject {
 	glowGraphics: Graphics;
 }
 
-/** The three parallax background layers (vignette lives on the stage). */
+/** The parallax background layers plus the vignette overlay. */
 export interface BackgroundLayers {
 	deepBackgroundContainer: Container;
 	nebulaContainer: Container;
 	starContainer: Container;
+	/** Static overlay on the stage; returned so a resize rebuild can destroy it. */
+	vignette: Graphics;
 }

src/routes/+layout.svelte

@@ -42,38 +42,97 @@
 	// terminate this block early or trip the Svelte ESLint parser.
 	const personLdScript = '<script type="application/ld+json">' + personJsonLd + '</' + 'script>';
 
+	// Set when a new worker is installed and waiting; drives the refresh prompt.
+	let updateReady = $state<(() => void) | null>(null);
+
 	onMount(() => {
-		// Register service worker for PWA support
-		if ('serviceWorker' in navigator) {
+		if (!('serviceWorker' in navigator)) return;
+
+		let reloading = false;
+		// The worker no longer calls skipWaiting() on install, so a new version
+		// waits instead of taking over a page running the previous deploy's JS.
+		// When it does take over, reload once so page and worker agree.
+		navigator.serviceWorker.addEventListener('controllerchange', () => {
+			if (reloading) return;
+			reloading = true;
+			location.reload();
+		});
+
 		navigator.serviceWorker
-				.register('/service-worker.js')
+			.register('/service-worker.js', { type: 'module' })
 			.then((registration) => {
-					if (import.meta.env.DEV) {
-						console.log('✨ Service Worker registered successfully:', registration.scope);
-					}
+				// The old code's comment claimed updates were checked periodically, but
+				// nothing ever called update(). Without this a long-lived tab only
+				// re-checks on navigation.
+				const hourly = setInterval(
+					() => {
+						registration.update().catch(() => {});
+					},
+					60 * 60 * 1000
+				);
+				window.addEventListener('pagehide', () => clearInterval(hourly));
 
-					// Check for updates periodically
 				registration.addEventListener('updatefound', () => {
 					const newWorker = registration.installing;
-						if (newWorker) {
+					if (!newWorker) return;
+
 					newWorker.addEventListener('statechange', () => {
-								if (newWorker.state === 'installed' && navigator.serviceWorker.controller) {
-									if (import.meta.env.DEV) {
-										console.log('🔄 New service worker available. Refresh to update.');
-									}
-								}
+						if (newWorker.state !== 'installed' || !navigator.serviceWorker.controller) return;
+						// A new version is ready and waiting. Previously this only logged,
+						// and in DEV only, so the SKIP_WAITING handler was dead code.
+						updateReady = () => newWorker.postMessage({ type: 'SKIP_WAITING' });
 					});
-						}
 				});
 			})
 			.catch((error) => {
 				console.warn('Service Worker registration failed:', error);
 			});
-		}
 	});
 </script>
 
 <svelte:head>
+	<!--
+		With JS disabled the canvas never mounts and SeoContent stays clipped to
+		1x1px, so the page renders pure black. This reveals the text version with
+		no JS involved.
+	-->
+	<noscript>
+		<style>
+			.sr-only {
+				position: static !important;
+				width: auto !important;
+				height: auto !important;
+				margin: 0 !important;
+				overflow: visible !important;
+				clip: auto !important;
+				white-space: normal !important;
+				max-width: 60rem;
+				padding: 2rem 1.5rem;
+				color: #e8e8f0;
+				line-height: 1.6;
+			}
+			html,
+			body {
+				overflow: auto !important;
+			}
+			.sr-only a {
+				color: #ffd700;
+			}
+			.sr-only h1,
+			.sr-only h2,
+			.sr-only h3 {
+				color: #ffd700;
+				margin: 1.25rem 0 0.5rem;
+			}
+			.sr-only ul {
+				padding-left: 1.25rem;
+			}
+			main {
+				display: none;
+			}
+		</style>
+	</noscript>
+
 	<!-- Favicon -->
 	<link rel="icon" href={favicon} />
 
@@ -150,3 +209,38 @@
 </svelte:head>
 
 {@render children()}
+
+{#if updateReady}
+	<div class="update-toast" role="status">
+		<span>A new version is available.</span>
+		<button onclick={() => updateReady?.()}>Refresh</button>
+	</div>
+{/if}
+
+<style>
+	.update-toast {
+		position: fixed;
+		right: 1rem;
+		bottom: 1rem;
+		z-index: 1100;
+		display: flex;
+		gap: 0.75rem;
+		align-items: center;
+		padding: 0.75rem 1rem;
+		border: 1px solid var(--color-gold);
+		border-radius: 8px;
+		background: linear-gradient(145deg, var(--panel-from) 0%, var(--panel-to) 100%);
+		color: #e8e8f0;
+		box-shadow: 0 4px 24px rgba(0, 0, 0, 0.6);
+	}
+
+	.update-toast button {
+		padding: 0.35rem 0.75rem;
+		border: 0;
+		border-radius: 6px;
+		background: var(--color-gold);
+		color: #12121a;
+		font-weight: 700;
+		cursor: pointer;
+	}
+</style>

src/routes/+page.svelte

@@ -1,13 +1,17 @@
 <script lang="ts">
 	import SkillTree from '$lib/components/SkillTree.svelte';
 	import SeoContent from '$lib/components/SeoContent.svelte';
+
+	// If the canvas can't come up (no WebGL, asset failure), the text version
+	// stops being a hidden mirror and becomes the page.
+	let renderFailed = $state(false);
 </script>
 
 <!-- Crawlable / screen-reader text version (visually hidden, prerendered). -->
-<SeoContent />
+<SeoContent revealed={renderFailed} />
 
-<main>
-	<SkillTree />
+<main class:hidden={renderFailed}>
+	<SkillTree onRenderFail={() => (renderFailed = true)} />
 </main>
 
 <style>
@@ -18,4 +22,8 @@
 		margin: 0;
 		padding: 0;
 	}
+
+	main.hidden {
+		display: none;
+	}
 </style>

src/service-worker.js

@@ -0,0 +1,120 @@
+/// <reference types="@sveltejs/kit" />
+
+// Lives in src/, not static/, so SvelteKit builds it and injects the manifest
+// below. That matters: `build` and `files` are generated from the actual output,
+// so the precache list can't drift, and `version` changes every deploy, so cache
+// names rotate automatically instead of needing a hand-edited version string.
+import { build, files, version } from '$service-worker';
+
+const CACHE = `atlas-of-skills-${version}`;
+
+// Content-hashed build output + everything in static/. Hashed assets are
+// immutable, so once cached they never need revalidating.
+const PRECACHE = [...build, ...files];
+
+self.addEventListener('install', (event) => {
+	event.waitUntil(
+		(async () => {
+			const cache = await caches.open(CACHE);
+			// Individually, not cache.addAll(): addAll is atomic, so a single 404
+			// failed the whole install and left the site with no offline support at
+			// all — silently.
+			const results = await Promise.allSettled(
+				PRECACHE.map((asset) => cache.add(new Request(asset, { cache: 'reload' })))
+			);
+			const failed = results.filter((r) => r.status === 'rejected').length;
+			if (failed) {
+				console.warn(`[sw] ${failed}/${PRECACHE.length} assets failed to precache`);
+			}
+		})()
+	);
+});
+
+self.addEventListener('activate', (event) => {
+	event.waitUntil(
+		(async () => {
+			// Drop every previous version's cache. Because the name embeds `version`,
+			// this now actually prunes on each deploy instead of accumulating stale
+			// hashed chunks forever.
+			const keys = await caches.keys();
+			await Promise.all(keys.filter((key) => key !== CACHE).map((key) => caches.delete(key)));
+			await self.clients.claim();
+		})()
+	);
+});
+
+/** Assets emitted by the build are content-hashed, so cache-first is safe. */
+const PRECACHED = new Set(PRECACHE);
+
+self.addEventListener('fetch', (event) => {
+	const { request } = event;
+
+	// Never touch non-GET (cache.put throws on them) or cross-origin.
+	if (request.method !== 'GET') return;
+	const url = new URL(request.url);
+	if (url.origin !== self.location.origin) return;
+
+	event.respondWith(handle(event, url));
+});
+
+async function handle(event, url) {
+	const { request } = event;
+	const cache = await caches.open(CACHE);
+
+	// Content-hashed build output: cache-first, it can never go stale.
+	if (PRECACHED.has(url.pathname) && build.includes(url.pathname)) {
+		const hit = await cache.match(url.pathname);
+		if (hit) return hit;
+	}
+
+	// Everything else — navigations and unhashed static files (icons, headshot,
+	// the résumé PDF) — is network-first. The old worker served these cache-first
+	// with no expiry, which meant replacing the résumé at the same URL never
+	// reached anyone who had already visited.
+	try {
+		const response = await fetch(request);
+
+		// Only cache real successes. A 404/500 body used to get written and then
+		// served as the offline fallback. Opaque/redirected responses throw on
+		// cache.put, so they're excluded too.
+		if (response.status === 200 && response.type === 'basic' && !response.redirected) {
+			// waitUntil so the write survives worker termination.
+			event.waitUntil(cache.put(request, response.clone()));
+		}
+		return response;
+	} catch {
+		const hit = await cache.match(request);
+		if (hit) return hit;
+
+		// Navigations fall back to the cached shell.
+		if (request.mode === 'navigate') {
+			const shell = await cache.match('/');
+			if (shell) return shell;
+		}
+
+		// Every other failure must still resolve to a Response. Returning
+		// undefined here (the previous behaviour for non-image assets) makes
+		// respondWith throw a TypeError and turns a soft failure into a hard one.
+		if (request.destination === 'image') {
+			return new Response(
+				'<svg xmlns="http://www.w3.org/2000/svg" width="120" height="120" viewBox="0 0 120 120">' +
+					'<rect width="120" height="120" fill="#05050a"/>' +
+					'<text x="60" y="64" fill="#ffd700" font-family="sans-serif" font-size="12" text-anchor="middle">Offline</text>' +
+					'</svg>',
+				{ status: 503, headers: { 'Content-Type': 'image/svg+xml', 'Cache-Control': 'no-store' } }
+			);
+		}
+
+		return new Response('Offline', {
+			status: 503,
+			headers: { 'Content-Type': 'text/plain', 'Cache-Control': 'no-store' }
+		});
+	}
+}
+
+// The page posts this after the user accepts an update prompt. Deliberately no
+// skipWaiting() in install: taking over a page whose JS came from the previous
+// deploy is how you get version skew.
+self.addEventListener('message', (event) => {
+	if (event.data?.type === 'SKIP_WAITING') self.skipWaiting();
+});

static/service-worker.js

@@ -1,116 +0,0 @@
-// Service Worker for PWA offline support
-const CACHE_NAME = 'atlas-of-skills-v2';
-const RUNTIME_CACHE = 'atlas-runtime-v2';
-
-// Assets to cache on install
-const PRECACHE_ASSETS = [
-	'/',
-	'/headshot.jpg',
-	'/kevin-riehl-resume.pdf',
-	'/robots.txt',
-	// Add icon paths when they're created
-	'/icons/pwa.svg'
-];
-
-// Install event - precache critical assets
-self.addEventListener('install', (event) => {
-	event.waitUntil(
-		caches.open(CACHE_NAME)
-			.then((cache) => cache.addAll(PRECACHE_ASSETS))
-			.then(() => self.skipWaiting())
-	);
-});
-
-// Activate event - clean up old caches
-self.addEventListener('activate', (event) => {
-	event.waitUntil(
-		caches.keys()
-			.then((cacheNames) => {
-				return Promise.all(
-					cacheNames
-						.filter((name) => name !== CACHE_NAME && name !== RUNTIME_CACHE)
-						.map((name) => caches.delete(name))
-				);
-			})
-			.then(() => self.clients.claim())
-	);
-});
-
-// Fetch event - network first, fallback to cache
-self.addEventListener('fetch', (event) => {
-	// Skip cross-origin requests
-	if (!event.request.url.startsWith(self.location.origin)) {
-		return;
-	}
-
-	// Network first strategy for HTML
-	if (event.request.mode === 'navigate') {
-		event.respondWith(
-			fetch(event.request)
-				.then((response) => {
-					// Clone response to store in cache
-					const responseClone = response.clone();
-					caches.open(RUNTIME_CACHE)
-						.then((cache) => cache.put(event.request, responseClone));
-					return response;
-				})
-				.catch(() => {
-					// Fallback to cache if network fails
-					return caches.match(event.request)
-						.then((cachedResponse) => {
-							if (cachedResponse) {
-								return cachedResponse;
-							}
-							// Return offline page if available
-							return caches.match('/');
-						});
-				})
-		);
-		return;
-	}
-
-	// Cache first strategy for assets (CSS, JS, images, icons)
-	event.respondWith(
-		caches.match(event.request)
-			.then((cachedResponse) => {
-				if (cachedResponse) {
-					return cachedResponse;
-				}
-
-				// Not in cache, fetch from network
-				return fetch(event.request)
-					.then((response) => {
-						// Don't cache if not a success response
-						if (!response || response.status !== 200 || response.type === 'error') {
-							return response;
-						}
-
-						// Clone response to store in cache
-						const responseClone = response.clone();
-
-						caches.open(RUNTIME_CACHE)
-							.then((cache) => {
-								cache.put(event.request, responseClone);
-							});
-
-						return response;
-					})
-					.catch(() => {
-						// Return fallback for images if network and cache fail
-						if (event.request.destination === 'image') {
-							return new Response(
-								'<svg xmlns="http://www.w3.org/2000/svg" width="200" height="200"><rect fill="#05050a"/><text x="50%" y="50%" text-anchor="middle" fill="#ffd700">Offline</text></svg>',
-								{ headers: { 'Content-Type': 'image/svg+xml' } }
-							);
-						}
-					});
-			})
-	);
-});
-
-// Message event - allow clients to skip waiting
-self.addEventListener('message', (event) => {
-	if (event.data && event.data.type === 'SKIP_WAITING') {
-		self.skipWaiting();
-	}
-});