docs: architecture map (initial 5-slice generation, 105 pages)

Five-slice navigable map of the entire codebase under
docs/architecture-map/. Each slice is a self-contained
breadcrumbed sub-tree:

  01-frontend (16)              Svelte/SvelteKit UI
  02-tauri-runtime (26)         src-tauri commands + lifecycle
  03-audio-transcription (16)   audio + transcription crates
  04-llm-formatting-mcp (19)    llm, ai-formatting, mcp, cloud
  05-core-storage-hotkey-build  core, storage, hotkey, workspace,
                          (26) CI, dev glue

Plus master README.md and data-flow-end-to-end.md tracing
audio bytes from microphone to FTS5 search to MCP read.

Generated by 5 parallel subagents on 2026/05/09 against
HEAD 3c47000. Each page has YAML frontmatter, file:line code
refs, sibling cross-links, plain-English summaries.

Aggregated debt surfaced (full lists in master README):
RB-08 macOS power assertion, schema head drift v14 vs v15,
VAD blocked on ort version conflict, streaming primitives
not wired into live.rs, no prompt versioning, MCP has no
auth, cloud-providers in-memory keystore, SettingsPage
2 484 LOC, commands/live.rs 1 737 LOC, dual theme system,
brand rename to Lumenote pending across the codebase.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

docs/architecture-map/01-frontend/pages/files.md

@@ -0,0 +1,63 @@
+---
+name: Files page
+type: architecture-map-page
+slice: 01-frontend
+last_verified: 2026/05/09
+---
+
+# Files page
+
+> **Where you are:** [Architecture map](../../README.md) → [Frontend](../README.md) → [Pages overview](../pages-overview.md) → Files
+
+**Plain English summary.** Drag and drop or browse local audio/video files for transcription. Same engine as live dictation, just file mode. On finish, results land in the page (preview text, segments) and into `addToHistory`.
+
+## At a glance
+
+- **Path:** `src/lib/pages/FilesPage.svelte`
+- **LOC:** 263
+- **Imports (selected):**
+  - Tauri: `invoke` (core), `listen` (event).
+  - Stores: `settings`, `addToHistory` from `page.svelte.ts`. `profilesStore`. `toasts` (transitive via store helpers).
+  - Components: `Card`, `EmptyState`.
+  - Utils: `exportTranscript`.
+  - External: `Upload` icon from `lucide-svelte`. `@tauri-apps/plugin-dialog` (lazy import).
+
+## What's in here
+
+### Drag and drop
+
+- `onMount` registers three Tauri events:
+  - `tauri://drag-drop` (`FilesPage.svelte:28`). Filters the dropped paths to supported extensions and starts transcription.
+  - `tauri://drag-enter` (`FilesPage.svelte:34`). Sets `isDragOver = true`.
+  - `tauri://drag-leave` (`FilesPage.svelte:35`). Sets `isDragOver = false`.
+- `onDestroy` calls each unlisten.
+
+### Browse
+
+- `handleBrowse()` lazy imports `@tauri-apps/plugin-dialog` and opens with the audio/video filter (`mp3, wav, m4a, mp4, flac, ogg, webm, mov, mkv`).
+
+### Transcription
+
+- Calls `invoke("transcribe_file", { ... })` (`FilesPage.svelte:76`). Receives transcript text + segments.
+- Optional `copy_to_clipboard` on completion.
+- Pushes result into history via the store helper.
+
+### State
+
+- `fileTranscript`, `segments`, `isDragOver`, `progress`, `progressText`, `fileName`, `error`, `transcribing`.
+
+## Tauri command surface
+
+`transcribe_file`, `copy_to_clipboard`. Plus dialog plugin.
+
+## Watch outs
+
+- The drag and drop events require the Tauri config to declare drag drop on the relevant window. If the events do not fire, check `tauri.conf.json` and slice 02.
+- Long files block the UI of this page until `transcribe_file` resolves. There is no abort.
+- The supported extensions list is duplicated between the file dialog filter and (presumably) the Rust side. Drift risk.
+- Multi file drag drop iterates serially. No queue UI.
+
+## See also
+
+- [Pages: dictation](dictation.md). The live counterpart.
+- [Frontend ↔ Tauri bridge](../frontend-tauri-bridge.md).