docs: document manual_notes.json (Granola-style live notes redesign)

docs/03-data-model.md

@@ -16,7 +16,8 @@ Default root: `%LOCALAPPDATA%\WhispAssist\` (user-configurable, FR-STORE-2).
     └── <meeting_id>\           # one folder per meeting (uuid)
         ├── audio.wav           # canonical recording — present ONLY if "Record" was on (ADR-0009)
         ├── transcript.json     # canonical transcript (segments+speakers+timings)
-        ├── notes.md            # user-editable Markdown notes
+        ├── manual_notes.json   # raw user-authored notes captured live during recording
+        ├── notes.md            # the final notes document: manual notes + transcript, merged at finalize
         ├── summary.json        # LLM summary, decisions, action items (if generated)
         └── briefs/             # feature briefs distilled from this meeting (ADR-0011), if any
             └── <brief_id>.json #   agent-ready spec served via the MCP `get_feature_brief` tool
@@ -24,9 +25,42 @@ Default root: `%LOCALAPPDATA%\WhispAssist\` (user-configurable, FR-STORE-2).
 
 Rule: while a meeting is in progress a working WAV is the source of truth for crash recovery. On
 finalize, it is **kept** as `audio.wav` if "Record this meeting" was on, or **deleted** if not
-(FR-REC-1/4) — deletion happens only after `transcript.json` is finalized. `transcript.json`,
-`notes.md`, and `summary.json` are **derived** and regenerable (regenerable only while the audio
-still exists — i.e. for recorded meetings).
+(FR-REC-1/4) — deletion happens only after `transcript.json` is finalized. `transcript.json` and
+`summary.json` are **derived** and regenerable (regenerable only while the audio still exists —
+i.e. for recorded meetings).
+
+`notes.md` is **generated once, at finalize**, by merging `manual_notes.json` (freeform notes
+typed live during the recording, plus any per-moment annotations — see below) with the rendered,
+speaker-tagged transcript (`notes::MarkdownNotes::merge`). After that it is the user's own
+document, freely editable via `update_notes` exactly like before this changed — nothing
+re-renders or overwrites it afterward. In particular, renaming or merging a speaker after finalize
+updates the `speakers` table and the live UI display, but does **not** retroactively rewrite text
+already baked into `notes.md` (same as any other manual edit isn't retroactively touched either —
+this was a pre-existing clobber bug this redesign also fixes: renaming a speaker used to silently
+overwrite the whole file). A crash-recovery finalize (T2.8) and a post-finalize batch
+re-transcription (T3.8) both re-render `notes.md` from scratch and so both re-read
+`manual_notes.json` from disk to fold the same manual notes back in.
+
+### `manual_notes.json`
+
+```jsonc
+{
+  "schema": 1,
+  "freeform_md": "string — the user's running notes, typed live in the Notes pane while recording",
+  "segment_notes": [
+    { "anchor_ms": 12345, "text": "string", "created_at": 1735000000, "updated_at": 1735000010 }
+  ]
+}
+```
+
+`segment_notes[].anchor_ms` is a timestamp into the recording (a clicked transcript segment's
+`start_ms`), not a segment id — a later batch re-transcription can renumber/regenerate segment
+ids, but never moves the moment in time a note was attached to. At merge time, each note is placed
+right after whichever transcript paragraph's time span contains its `anchor_ms`; a note whose
+anchor doesn't land inside any paragraph surfaces under an "Other notes" section instead of being
+silently dropped. Written to disk on every edit via `update_live_notes`/`set_segment_note`
+(`04-api-contracts.md`) — live-session only, same write-through-for-crash-safety spirit as
+`transcript.json` accumulating during recording.
 
 ## SQLite schema (`wa.db`)