Frontend perf + correctness: capture plan in tasks/

[ajslater]

Summary

Plan-only PR covering the codex frontend (~12k LOC components + ~3.5k LOC stores/api/plugins, 170 .js/.vue files). Mirrors the importer-perf / janitor-perf plan-capture pattern (#621, #625, #627, #635).

Investigation methodology

Surface too big for a single sweep. Fanned the investigation across four parallel sub-agents — browser, reader, API+socket, admin+metadata — plus build-config review by hand. ~64 raw findings synthesized, deduplicated, and grouped into four tiers and five sub-plans.

Headline findings (correctness)

Two confirmed silent-failure bugs on the read path:

components/reader/pager/page/page.vue:104

mounted() {
  setTimeout(function () {           // non-arrow: `this` is the timer
    if (!this.loaded) this.loading = true;
  }, PROGRESS_DELAY_MS);
}

The load-progress spinner literally never shows. Has been broken since the file was written.

stores/reader.js:486

if (!arcs.length) {
  // No arcs is a 500 from the mtime api
  arcs.push({ r: "0" });             // wrong shape; sibling code uses { group, pks }
}

The fallback the comment says was added to avoid a 500 itself returns a 500.

Plus 11 more bugs of varying severity: rapid-click races on loadBrowserPage / loadBooks, iOS PWA blob URL leak, unbounded search history growth, double-rendering of filter list items, etc.

Plan structure

Sub-plan	Items	Focus	Approx LOC
01 correctness-bugs	13 bugs	Race conditions, leaks, broken-since-conception	~150
02 request-dedup	11 items	AbortController, pending-promise dedup, WS exp backoff, CSRF cache	~200
03 hot-path-renders	19 items	Per-render alloc, deep watchers, layout thrash, theme lookups	~230
04 reader-scroll-perf	7 items	Prefetch window, scroll throttle, bookmark debounce	~150
05 bundle-and-startup	2 items	Vendor chunk split, parallel cold-boot fetches	~50

Suggested ship order: 01 → 02 → 03 → 04 → 05. Correctness first, then network dedup, then per-render optimizations, then reader-specific, then build/startup.

Test plan

• Review 00-meta.md for surface-map accuracy and finding triage
• Confirm the sub-plan groupings make sense
• Flag any items that should be promoted/demoted between tiers
• Approve as planning artifact (no code changes)

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