fix(terminal): four silent-failure paths — renderer freeze, replay race, reconnect gap, unbounded fetches

CLAUDE.md

@@ -334,6 +334,12 @@ Frontend JS modules have `@fileoverview` with `@dependency`/`@loadorder` tags. L
 
 **Shell keyboard accessory bar + one-shot Ctrl** (issue #262, `keyboard-accessory.js`): a **shell**-mode session automatically swaps the mobile accessory bar for terminal controls (Ctrl, Esc, Tab, four arrows, paste, dismiss); every other mode keeps the agent bar. `setMode()` now records the user's `extendedKeyboardBar` preference as the **base** layout and `refreshForActiveSession()` (called from `selectSession`) resolves base-vs-shell, so a settings save during a shell session cannot yank the bar away and switching back restores the user's choice. ⚠️ **Ctrl is a ONE-SHOT modifier applied in `terminal.onData`, not in a keydown handler**: a virtual keyboard emits no usable key events, so the character only exists as onData text. The hook sits AFTER `shouldSuppressTerminalQueryResponse` (xterm answers DA/CPR through onData too, and one of those would silently spend the modifier) and BEFORE every send path, so the control byte follows the normal control-char route. ⚠️ **Not every onData chunk is a keystroke**, and the query filter is not enough on its own: xterm ALSO emits mouse and focus reports on its own initiative, so the hook skips them via `isTerminalFocusOrMouseReport()` (they still reach the PTY, they just don't count as the next key). The mouse half is live — a shell session keeps the NARROW strip, so mouse DECSETs reach the browser and one tap while vim/htop runs spent the armed modifier silently (measured). The focus half is defense in depth: `FOCUS_ESCAPE_FILTER` in `session.ts` strips `\x1b[?1004h` from every PTY read, so `sendFocusMode` never turns on today; if it ever did, the bar's own post-key refocus would emit `\x1b[I` and eat the modifier before the user typed. ⚠️ It must disarm on ALL of: use, second tap, any other accessory key, session switch, keyboard dismissal, and a layout swap; a modifier left armed turns the next innocent keystroke into a control byte. ⚠️ **onData is not the only input path** — with `cjkInputEnabled` on, the CJK textarea owns the keyboard (onData returns early for everything it swallows, and the focus router sends `terminal.focus()` there, which is where the bar refocuses after every key), so `_handleCjkInput()` applies the modifier too. It is that module's single choke point to the PTY, so one call covers typed characters, IME flushes, Enter, backspace and arrows. Without it an armed modifier could neither fire NOR be spent, and survived to a later keystroke. Mapping is `ctrlByteFor()` (`code & 0x1f` over @A-Z[\]^_ and a-z, plus Ctrl+Space=NUL / Ctrl+?=DEL); characters with no control equivalent pass through unchanged, like a hardware keyboard. ⚠️ The armed style is `.accessory-btn.accessory-btn-ctrl.armed` (0,3,0) in BOTH stylesheets, and it cannot outrank mobile.css's light-skin repaint at **(0,3,1)** (`:is()` inherits its most specific argument, and that list holds `.btn-toolbar.btn-shell`) — so that rule excludes the state by hand as `.accessory-btn:not(.armed)`. Without the exclusion the armed button renders identically to a resting one on all four light skins, which is worse than no armed style at all.
 
+**Terminal resilience: replay clears, renderer liveness, fetch deadlines**: three rules that each close a way the terminal silently stops being correct. ⚠️ **A replay clear MUST be in-stream, never `reset()`/`clear()`.** xterm's `write()` is asynchronously queued while `Terminal.reset()` is synchronous and, per upstream, "does not clear input buffers and does not reset the parser" — so bytes queued just before a reset are parsed AFTER it and fuse into the snapshot written next. **Measured** against the real xterm in this repo: `write('p8'); reset(); write('rmissions')` renders `p8rmissions`; the queued `\x1bc` renders `rmissions` and clears scrollback. `_resetTerminalForReplay()` (app.js) is the ONE clear, a single queued `\x1bc` (RIS), and all three replay paths go through it; RIS rather than `\x1b[3J\x1b[H\x1b[2J` because the erase leaves modes, charsets, scroll regions and SGR state alone. Callers may still chunk the content — ordering in the queue is what matters, not writing it in one call. ⚠️ **The renderer watchdog reads xterm privates and CANNOT be covered by the gate.** `_kickRenderer()` (terminal-ui.js) cancels a stale `_core._renderService._renderDebouncer._animationFrame` and forces a repaint. **Verified against xterm 6.0.0** (jsdom, after `open()`): the field path resolves, a forced stale handle genuinely makes `refreshRows` a no-op, and the kick schedules a fresh frame. **Reasoned, not reproduced here**: the premise that iOS discards scheduled rAF callbacks when a PWA backgrounds, which is what leaves the handle stale — that half wants a real-device pass. Codeman has exactly ONE xterm for the whole page load, so one backgrounding would wedge it until a reload. `_renderService` only exists after `open()`, which needs a real DOM, and the gate runs in node — so `test/xterm-private-api.test.ts` pins the RESOLVED lockfile version (not the `^6.0.0` range, which a real upgrade slips through) and a bump means re-verifying by hand. Every access is optional-chained on purpose: a renamed field must degrade to a no-op, never throw on a 2s timer. ⚠️ **Every terminal capture carries a deadline, and the helper reads the BODY** (`_fetchTerminalCapture`, app.js). `await fetch()` settles on response HEADERS, so clearing the timer there leaves the body — the multi-megabyte `?full=1` capture this exists for — unbounded: **measured** at 4026ms under a 1000ms deadline before the fix. The helper therefore returns `{json, headers, headersAt}` rather than a `Response`, and `_terminalCaptureInflight` is scoped the same way so a body still streaming counts toward a capture starting beside it. It degrades to a plain fetch where `AbortController` is missing — the deadline is a safety net, not a dependency. Tests: `test/terminal-resilience.test.ts` (pure decisions), `test/xterm-private-api.test.ts`.
+
+**WebSocket output-gap reconcile** (`_wsOutputGapSession`, app.js): terminal OUTPUT frames carry no sequence number (input frames do — `seq`+`cid`, at-most-once, ACKed), so a dropped socket leaves a hole nothing replays. ⚠️ **The gap is narrower than "the device went offline"**: if the network drops, SSE drops with it and `handleInit`'s keepTerminal branch already calls `_onSessionNeedsRefresh`. The uncovered case is the WS dying while SSE stays up (half-open socket, proxy idle-timeout, ping timeout), because `_onSSETerminal` discards every SSE terminal frame while `_wsReady` is true and `_wsReady` only flips in `ws.onclose`. Reaching `onclose` at all means the drop was unintentional (`_disconnectWs` nulls the handler first), so the session is marked and the next successful open reconciles. ⚠️ **The marker must be cleared by EVERY path that repaints that session's buffer** — `_markTerminalBufferReconciled()` is called from `_onSessionNeedsRefresh`'s finally, from `selectSession` after its load, and from `_cleanupSessionData`. `selectSession` loads the buffer and only THEN calls `_connectWs`, so without that clear the socket opening afterwards replays the whole buffer a second time on top of the one just written. Sequencing the output frames is the real fix and is not done. This is reasoned from the code path, not observed on a device.
+
+**Service worker: precache and cache key are BUILD-GENERATED** (`sw.js` + `scripts/build.mjs`): the build content-hashes assets and rewrites two exact declarations in `sw.js` — `const BUILD_ID = 'dev';` and `const HASHED_ASSETS = [];`. ⚠️ **Each must appear exactly once or the build THROWS**, which is deliberate: the list used to be hand-maintained with PRE-hash names, so every entry 404'd in production and `cache.add().catch(() => {})` hid it (15 of 23 verified failing against a running instance). The dev literals are valid on their own, so dev serves an unrewritten worker with an empty precache. ⚠️ **`caches.match` must pass `ignoreSearch: true`**: `renderIndexHtml` runs `cacheBustAssets`, which appends `?v=<mtime>` to every same-origin `.js`/`.css` reference INCLUDING content-hashed names, so the page requests `/app.<hash>.js?v=<mtime>` while the cache holds `/app.<hash>.js`. Without it no precached entry is reachable and the install downloads ~1.3MB that can never be served — once per deploy, since `CACHE_NAME` now carries the build id. That per-build key is what makes `activate`'s cleanup actually delete anything; it used to be the constant `'codeman-v1'`, so assets from every past release accumulated forever. Contract pinned by `test/sw-precache-manifest.test.ts`, which PARSES the `HASHABLE` list out of `build.mjs` rather than copying it.
+
 **Dismissing the on-screen keyboard** (PRs #279/#280, `terminal-ui.js`): the terminal parks focus on a hidden textarea that nothing used to release, so TWO gestures now blur it, and they own different regions. **(1)** `_installMobileKeyboardDismiss()` — a document-level `touchend` that fires only while the terminal input actually holds focus, **never inside `#terminalContainer`** (tap classification owns that) and **never on a control** (`MOBILE_KEYBOARD_DISMISS_EXEMPT_SELECTOR`, matched with `closest()` so an icon inside a button counts). Session tabs are covered by the selector's `[tabindex]:not([tabindex="-1"])` arm, which is what stops a tab tap from blurring and then being re-focused by `selectSession()`. **(2)** In `_handleMobileTerminalTap`, a second tap on **inert `content`** (`startedWithTerminalFocus`) blurs instead of re-focusing. ⚠️ Scoped to `content` on purpose: the prompt row (`input`) keeps focus-then-position so a second tap still places the caret, and actionable rows blur earlier via `_isActionableMobileTerminalTap`. ⚠️ **A scroll ends in `touchend` too** — dismissing there closes the keyboard and drops the composer mid-read, so travel is tracked from `touchstart` and multi-touch is never a tap. Both classifiers MUST share one threshold: `initTerminal`'s `TAP_THRESHOLD` reads `MOBILE_KEYBOARD_DISMISS_TAP_SLOP`, since a gesture the terminal calls a scroll and the dismiss handler calls a tap is exactly that bug. ⚠️ **The gate excludes `test/mobile/**`, so CI cannot see the only test covering (1)** — run `npm run test:mobile -- test/mobile/keyboard.test.ts` by hand and diff the FAIL list against master. (Not `npm test --`: the gate's config excludes that path, so a file filter pointing into it matches nothing and exits green having run zero tests.) That blind spot is why merging the two PRs, which conflicted semantically but not textually, produced a red suite with two green CI checks.
 
 **Phone toolbar: Enter replaces Shell** (post-1.8.0): inside `@media (max-width: 599px)` `btn-shell` is `display:none` and `btn-enter` takes its slot (`order: 4`); starting a shell moved into the Run dropdown (`Terminal / Shell` → `setRunMode('shell')` → `run()` → `runShell()`, button label "Run SH"). `runMode` is `z.string().max(20)` server-side, so new modes need no schema change. Desktop and tablet keep the green Run Shell button unchanged.

scripts/build.mjs

@@ -146,10 +146,44 @@ console.log('\n[build] content-hash cache busting');
     html = html.replaceAll(`"${original}"`, `"${hashed}"`);
   }
   writeFileSync(join(distPublic, 'index.html'), html);
+
+  // Rewrite sw.js from the SAME manifest that just renamed the files.
+  //
+  // The service worker's precache list used to be maintained by hand with the
+  // pre-hash names, so after this step every entry in it pointed at a file that
+  // no longer existed and `cache.add(...).catch(() => {})` hid it. Deriving it
+  // here is the only way the two cannot drift.
+  //
+  // The cache key gets the build hash for the same reason: `activate` deletes
+  // every cache that is not the current one, so a constant key meant that
+  // cleanup never ran and hashed assets from every past release piled up.
+  const swPath = join(distPublic, 'sw.js');
+  let sw = readFileSync(swPath, 'utf8');
+  const hashedAssets = Object.values(manifest);
+  const buildId = createHash('md5').update(hashedAssets.join('|')).digest('hex').slice(0, 12);
+  // Rewrite the two declarations. Anchored on the full `const … = …;` text so
+  // each pattern occurs exactly once and cannot collide with prose in sw.js's
+  // own comments — an earlier cut used bare `__BUILD_ID__` sentinels and the
+  // first match landed in the comment that documented them, leaving the real
+  // constant untouched and still producing a plausible-looking cache key.
+  const swEdits = [
+    ["const BUILD_ID = 'dev';", `const BUILD_ID = '${buildId}';`],
+    ['const HASHED_ASSETS = [];', `const HASHED_ASSETS = [${hashedAssets.map((p) => JSON.stringify(p)).join(', ')}];`],
+  ];
+  for (const [from, to] of swEdits) {
+    const hits = sw.split(from).length - 1;
+    if (hits !== 1) {
+      throw new Error(`sw.js: expected exactly one \`${from}\`, found ${hits} — precache would ship stale`);
+    }
+    sw = sw.replace(from, to);
+  }
+  writeFileSync(swPath, sw);
+
   console.log('  Hashed files:');
   for (const [orig, hashed] of Object.entries(manifest)) {
     console.log(`    ${orig} -> ${hashed}`);
   }
+  console.log(`  sw.js: cache bucket codeman-${buildId}, ${hashedAssets.length} precached assets`);
 }
 
 // 6. Compress with gzip + brotli