Format code with Prettier (8 modified files from H1 decomposition)

Aligns with CC2 enforcement: ESLint + Prettier + noImplicitAny now enforced.

Co-Authored-By: Claude Haiku 4.5 <noreply@anthropic.com>

CODE-AUDIT.md

@@ -51,6 +51,18 @@ preview mock + Settings defaults — `DEFAULT_SETTINGS` in `@shared`, one typed
 eslint green; the touched files are prettier-clean (3 pre-existing format violations in
 DownloadOptionsForm/LibraryView/SettingsView are untouched and out of scope).
 
+**Session 2026-07-01 (main-process structure — the H1-adjacent decompose batch):** **L2** (the ~200-line
+flat IPC block moved into one `src/main/ipc.ts` `registerIpcHandlers(getMainWindow)`; index.ts is now
+lifecycle + window creation and imports the shared theme helpers from ipc.ts), **L69** (path helpers split
+into `src/main/paths.ts`; settings.ts is now purely the electron-store layer), **L10** (a main-process
+`src/main/constants.ts` centralizes the spawn timeouts, execFile buffers, stderr tail, and the three store
+caps — nine modules migrated off bare literals), **CL2** (`buildArgs` → single `BuildArgsInput` object),
+**CL3** (`startDownload`'s stream/close/error/watchdog wiring extracted into `wireChildProcess`), and **L1**
+(the scheduled-download promoter tick moved from store-module load into an App `useEffect` so a store import
+no longer starts a stray timer). All verified: typecheck (node+web) + 253 tests + eslint + production build
+green; the touched files are prettier-clean (the 8 remaining prettier warnings are all pre-existing,
+untouched files — DownloadOptionsForm/SettingsView/settings/*Card).
+
 **Deliberately deferred** (need live-app/visual verification or are larger refactors the
 audit itself defers to 1.x): the wire-or-cut features (M5/M6/UX1), the god-file/store
 refactors (C1, C2, H1), the SIMP* helpers + shared-UI-token work, the CC* consolidations,
@@ -439,9 +451,20 @@ token system + shared primitives (UI/SIMP — high value, larger effort) · i18n
 
 ## Low
 
-- [ ] **L1 — Module-load `setInterval` in `store/downloads.ts`** runs on import (incl. tests/preview).
-- [ ] **L2 — `index.ts` flat IPC registration (~150 lines)** — let each main module export its own
-  `register(ipcMain)`.
+- [x] **L1 — Module-load `setInterval` in `store/downloads.ts`** runs on import (incl. tests/preview).
+  *Fixed: the scheduled-download promoter tick moved out of store-module scope into an `App.tsx`
+  `useEffect` (interval `SCHEDULE_TICK_MS`, cleared on unmount). Importing the store in tests/preview no
+  longer starts a stray never-cleared timer; the store keeps the `promoteDueScheduled` action, App owns the
+  cadence. (The preview `startFakeTicker` interval is created on demand per launched item, not at load, so
+  it was already fine.)*
+- [x] **L2 — `index.ts` flat IPC registration (~150 lines)** — let each main module export its own
+  `register(ipcMain)`. *Fixed: the whole ~200-line handler block moved into one dedicated
+  [ipc.ts](src/main/ipc.ts) exporting `registerIpcHandlers(getMainWindow)` — the single place the renderer's
+  IPC contract is wired. index.ts now imports it (plus the three shared theme helpers `resolveBackgroundMode`
+  /`applyNativeTheme`/`getSystemThemeInfo`, also moved to ipc.ts) and shed ~50 imports it only needed for the
+  handlers, leaving it as app-lifecycle + window creation. The window-coupled handlers (folder picker,
+  theme-synced background, taskbar progress) take the live window via the `getMainWindow` accessor rather
+  than a captured `mainWindow`.*
 - [x] **L3 — Stale comments.** `getYtdlpVersion` JSDoc still calls it the "Step-1 spike";
   `vitest.config.ts` claims tests "only exercise buildArgs.ts" (9 test files now exist).
 - [x] **L4 — `electron-builder.yml` nits.** `copyright: yt-dlp frontend` is not a copyright
@@ -458,9 +481,16 @@ token system + shared primitives (UI/SIMP — high value, larger effort) · i18n
   Diagnostics keys by `id + occurredAt` while every other list keys by `id` alone.
 - [x] **L9 — Thumbnail box sizes not shared.** Four hand-tuned 16:9 boxes (120×68, 108×64, 72×44,
   60×34) with no shared aspect/size constant.
-- [ ] **L10 — Scattered magic numbers.** Timeouts/caps spread across modules (probe 60s, indexer
+- [x] **L10 — Scattered magic numbers.** Timeouts/caps spread across modules (probe 60s, indexer
   180s, probeMeta 30s, update-idle 60s; MAX_ENTRIES 500/200, MAX_TEMPLATES 100, MAX_ITEMS 20000).
-  Consider a central constants module.
+  Consider a central constants module. *Fixed: a main-process [constants.ts](src/main/constants.ts) now
+  holds the process-spawn timeouts (`VERSION_TIMEOUT_MS`, `META_PROBE_TIMEOUT_MS`, `PROBE_TIMEOUT_MS`,
+  `INDEX_TIMEOUT_MS`, `YTDLP_UPDATE_TIMEOUT_MS`, `FEED_FETCH_TIMEOUT_MS`, `STALL_TIMEOUT_MS`), the execFile
+  `maxBuffer` sizes (`META`/`PROBE`/`INDEX_MAX_BUFFER`), `STDERR_TAIL_BYTES`, and the three hand-rolled store
+  caps (`ERRORLOG_MAX_ENTRIES`, `TEMPLATES_MAX`, `MEDIA_ITEMS_MAX`). download/ffmpeg/indexer/probe/ytdlp/sync/
+  errorlog/templates/sources import from it instead of bare literals. Values already single-sourced in the
+  shared contract (`HISTORY_MAX_ENTRIES`) and updater.ts's already-named local timeouts were left in place —
+  they aren't scattered literals.*
 - [x] **L11 — "Queue (N)" overcounts.** DownloadsView's header count is `items.length` (includes
   completed/error/canceled), not the active queue.
 - [x] **L12 — Command palette polish.** No scroll-into-view for keyboard selection in the 50vh
@@ -568,8 +598,12 @@ token system + shared primitives (UI/SIMP — high value, larger effort) · i18n
 - [ ] **L67 — Onboarding has no Skip and can't be revisited** (no "show tips again").
 - [x] **L68 — Background-running notification fires once per process** (`notifiedBackground` never
   resets) — won't remind on later window closes.
-- [ ] **L69 — `settings.ts` mixes path helpers with persistence** (`getDefaultMediaDir`/
-  `ensureMediaDirs`/`getDownloadArchivePath` alongside the store) — split a `paths.ts`.
+- [x] **L69 — `settings.ts` mixes path helpers with persistence** (`getDefaultMediaDir`/
+  `ensureMediaDirs`/`getDownloadArchivePath` alongside the store) — split a `paths.ts`. *Fixed: the three
+  path helpers moved to [paths.ts](src/main/paths.ts); settings.ts is now just the electron-store persistence
+  layer (its now-unused `path`/`fs` imports dropped). download.ts and index.ts import the helpers from
+  `./paths`. `applyLaunchAtStartup` stays in settings.ts — it's OS login-item integration referenced by
+  `applySettings`, not a path helper.*
 - [x] **L70 — `crypto.randomUUID` fallback is effectively unreachable** in Electron/Node 26
   (`typeof crypto !== 'undefined'` is always true) — dead defensive branch (see M7). *Fixed with M7: the
   branch now lives once in `newId` (kept so the fn is total in any host) and is covered by a test that stubs
@@ -968,23 +1002,51 @@ root cause is already filed.
   subtitles, SponsorBlock), passed via `AddOptions.options` → `startDownload`. The panel also carries the
   M6 incognito checkbox and sits beside the M5 command preview. Overrides are one-shot: they reset to the
   global defaults after each download (matching Trim/Schedule).*
-- [ ] **UX2 — "Fetch" vs "Download" is ambiguous, and Enter does the wrong thing.** Two unlabeled
+- [x] **UX2 — "Fetch" vs "Download" is ambiguous, and Enter does the wrong thing.** Two unlabeled
   icon buttons (magnifier = "Fetch", clipboard = "Paste") sit next to "Download"; a first-timer can't
   tell that Download works without Fetch. Pressing **Enter** in the URL field runs a *probe*, not the
   download (L27) — violating "type URL + Enter = go". **Fix:** label the action, make Enter download
   (or fetch-then-download), and present Fetch as optional ("Preview formats").
-- [ ] **UX3 — Library "Index" is jargon and a hidden two-stage workflow.** Pasting a channel URL in
+  *Fixed in [DownloadBar.tsx](src/renderer/src/components/DownloadBar.tsx): **Enter is now "go"** — it
+  starts the download (or adds the fetched playlist when the playlist panel is open) instead of probing;
+  probing stays an explicit, optional click. The magnifier button is relabeled from "Check URL" to
+  **"Preview available formats (optional)"** (both its tooltip and `aria-label`), and the URL placeholder
+  now reads "Paste a video or playlist URL, then press Enter to download" so it's clear Download works
+  without Fetch. `download()` already enqueues with the presets when nothing has been probed, so the
+  Enter-downloads path needs no probe. (resolves L27's Enter inconsistency too.)*
+- [x] **UX3 — Library "Index" is jargon and a hidden two-stage workflow.** Pasting a channel URL in
   the Downloads bar tries to treat it as one item; whole channels belong in the Library tab, but
   nothing signposts that. "Index" reads like "Download" but only catalogs — you must then expand,
   select, and Download. **Fix:** rename to "Add channel/playlist," and after indexing surface a clear
   "Download N videos" next step; detect channel URLs in the Downloads bar and suggest the Library.
+  *Fixed across three seams. **(1) De-jargoned the Library** ([LibraryView.tsx](src/renderer/src/components/LibraryView.tsx)):
+  the primary button is now **"Add"** (was "Index"), "Re-index" → **"Refresh"**, and the header
+  description / empty state / placeholder / error copy drop "index" for "add". The post-add next step
+  already exists — `indexSource` auto-selects the new source so its card expands with a prominent
+  "Download N pending" primary button. **(2) Channel detection in the Downloads bar** — a new pure
+  [`looksLikeChannelOrPlaylist`](src/renderer/src/lib/urlHelpers.ts) (conservative: only clear YouTube
+  channel/dedicated-playlist shapes; a `/watch` video, even with a `list=`, is never flagged and keeps
+  working in the bar) drives a dismissible brand-tinted nudge in
+  [DownloadBar.tsx](src/renderer/src/components/DownloadBar.tsx): "This looks like a channel or playlist.
+  Add it in the Library…" with an **Open in Library** action. **(3) The handoff** goes through a small
+  new [store/nav.ts](src/renderer/src/store/nav.ts) (App's tab state moved into it) that carries a
+  one-shot `pendingLibraryUrl`; the Library consumes it on mount to pre-fill its add field. Unit-tested
+  (`looksLikeChannelOrPlaylist` in `test/clipboardLink.test.ts`) and verified end-to-end in the browser
+  preview (channel URL → nudge → Open in Library → Library tab with the URL pre-filled).*
 - [x] **UX4 — Destructive actions have no confirmation and no undo** (L13). "Clear history,"
   "Clear log," "Remove source" (deletes an entire indexed channel + items), and "Delete selected"
   are all one click. A user exploring can wipe data irreversibly. **Fix:** confirm destructive/bulk
   deletes (or offer an undo toast).
-- [ ] **UX5 — First run can't choose the download folder.** [Onboarding.tsx](src/renderer/src/components/Onboarding.tsx)
+- [x] **UX5 — First run can't choose the download folder.** [Onboarding.tsx](src/renderer/src/components/Onboarding.tsx)
   only *describes* Documents\Video/Audio — there's no picker (the ROADMAP claims one). The user must
   later discover Settings → Downloads. **Fix:** put the folder picker in onboarding as documented.
+  *Fixed: the "Where downloads go" block in [Onboarding.tsx](src/renderer/src/components/Onboarding.tsx)
+  now has interactive Video and Audio rows — each shows the current folder (or the `Documents\Video` /
+  `Documents\Audio` default) with a **Choose…** button that opens the OS picker via the settings store's
+  `chooseDir` (the same proven path DownloadsCard uses, seeded at the current value — W5). Picking a
+  folder persists immediately, so the choice is already saved when the user clicks "Get started";
+  leaving it untouched keeps the Documents defaults. Verified in the browser preview with onboarding
+  forced on.*
 
 ### Medium — confusion, feedback & organization
 
@@ -1258,10 +1320,18 @@ filed. Several listed categories are **N/A** to this stack and worth recording s
   `'path|'` are hard-coded in `buildArgs.ts` (`PROGRESS_TEMPLATE` / `--print after_move:path|…`) and again
   in `download.ts` (`line.startsWith('prog|')` / `'path|'`). Change one and the other breaks silently.
   **Fix:** export shared marker constants from one module.
-- [ ] **CL2 — Long positional parameter list.** `buildArgs(opts, outputTemplate, o, binDir, access,
-  extraArgs)` takes six positional args (and `o` vs `opts` is easy to swap). **Fix:** pass a single options object.
-- [ ] **CL3 — Large method: `startDownload`** (~130 lines) bundles spawn + dual metadata path + four inline
-  `child` event handlers. **Fix:** extract the stdout-parse + close/error wiring (pairs with CC3's spawn-stream helper).
+- [x] **CL2 — Long positional parameter list.** `buildArgs(opts, outputTemplate, o, binDir, access,
+  extraArgs)` takes six positional args (and `o` vs `opts` is easy to swap). **Fix:** pass a single options
+  object. *Fixed: `buildArgs(input: BuildArgsInput)` now takes one named object (`opts`/`outputTemplate`/
+  `options`/`binDir`/`access`/`extraArgs?`) destructured at the top, so callers can't transpose the two
+  path-like strings or `opts`/`options`. download.ts's `buildCommand` and both test harnesses updated.*
+- [x] **CL3 — Large method: `startDownload`** (~130 lines) bundles spawn + dual metadata path + four inline
+  `child` event handlers. **Fix:** extract the stdout-parse + close/error wiring (pairs with CC3's spawn-stream
+  helper). *Fixed: the stdout/stderr parse, the close/error handlers, and the B1 idle watchdog moved into a
+  `wireChildProcess({ wc, opts, rec, cleanup, getTitle })` helper in [download.ts](src/main/download.ts).
+  `startDownload` is now a linear pre-flight (binary checks → URL normalise → concurrency guard → cookies →
+  spawn → metadata probe → wire). `getTitle` is a getter because the parallel metadata probe may fill the
+  resolved title in after wiring is set up. Behaviour unchanged.*
 - [ ] **CL4 — Deep nesting: `updater.downloadAppUpdate`** — Promise → `net.request` → `response` → `data`
   with nested conditionals/teardown is the hardest-to-follow block. **Fix:** extract a `streamToFile` helper.
 - [x] **CL5 — Superfluous exports.** `PROGRESS_TEMPLATE` (L167) and `getManagedBinDir` are `export`ed but