Moments: per-user saved pages and regions with one category (BL-0055)

Reader: bookmark button and M save the page (Flow: page at the reading
line, Book: the spread) with an optional dragged region, exactly one
category (Twist, Hot, Awesome, Cute, Funny, Feels) and a note. I now
toggles the bars; ? lists all keys. Keys dispatch through public/keys.js,
which also feeds the new Settings -> Keyboard shortcuts section.

Manga page: "Your moments" strip of crops (story or recent order,
category filters), viewer with step, full page, edit, delete and
"Open in reader" (read.html ...&p=). Moments point at pages by file
name and show "page moved" when the file is gone. Private per user.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

docs/architecture.md

@@ -151,6 +151,10 @@ This keeps ids human-readable and derivable without a database. The price: renam
   "follows":   { "admin": { "Moon Garden": true } },
   "notes":     { "admin": [ { "id": "a1b2c3d4e5f6", "t": 1790797300000, "m": "Moon Garden", "c": "2/6",
                               "text": "Moon Garden · Ch. 6: Frost", "read": false } ] },
+  "moments":   { "admin": [ { "id": "9f1c2b3a4d5e", "m": "Moon Garden", "c": "1/2", "v": "c0002 Roots [MangaDex]",
+                              "i": [4], "f": ["0005.png"], "sha": ["<sha256 of the file>"],   // pages, left to right as displayed (1 or 2)
+                              "region": { "x": 0.1, "y": 0.5, "w": 0.5, "h": 0.25 },          // fractions of the page(s); null = whole page
+                              "cat": "awesome", "note": "", "t": 1790797400000 } ] },
   "votes":     { "Moon Garden": { "1/2": { "c0002 Roots [Official]": { "admin": 1, "reader": -1 } } } },
   "known":     { "Moon Garden": ["1/1", "1/2", "1/2.5", "..."] }   // every chapter id ever seen (append-only)
 }
@@ -201,6 +205,9 @@ All requests and responses are JSON. POSTs require `Content-Type: application/js
 | `POST /api/unread` `{m, c}` | user | Forget progress for a chapter |
 | `POST /api/vote` `{m, c, v, value: 1\|-1\|0}` | user | Vote a version; returns the re-ranked versions |
 | `POST /api/follow` `{m, on}` | user | Follow a manga for notifications |
+| `GET /api/moments?m=` | user | The caller's moments of that manga in story order: category, note, region, chapter, `order`, page images, `missing` when a page file is gone. `/api/chapter` also lists the caller's moments on the opened version |
+| `POST /api/moments` `{m, c, v, pages, region, cat, note}` | user | Save a moment: `pages` are 1–2 indexes left to right as displayed, `cat` one of `twist hot awesome cute funny feels` (required), `region` fractions or null |
+| `POST /api/moments/update` `{id, cat?, region?, note?}` · `POST /api/moments/delete` `{id}` | user | Edit or delete one of the caller's own moments (another user's id is `404`) |
 | `GET /api/notifications` · `POST /api/notifications/read` `{id \| all}` | user | Notification list and read state |
 | `GET /api/admin` | admin | Users, last scan result, library path |
 | `POST /api/admin/rescan` `{full}` | admin | Scan now, and wait for the result |
@@ -323,12 +330,12 @@ mode       = adapt && intended ∉ compatible ? compatible[0] : intended
 | Horizontal swipe ≥ 50 px within 800 ms (paged, not zoomed in) | Previous/next |
 | Ctrl + wheel, touchpad pinch, Safari gesture events, two-finger pinch | Continuous page zoom 20–600 %, snapping to 100 % within ±1 %, anchored at the pointer or finger midpoint. Browser zoom is suppressed only over the pages |
 | Mouse drag (moved ≥ 6 px) | Pan; the following click is swallowed. Hand cursor when the content is larger than the screen |
-| Keys | Arrows follow the direction; Space/PageDown/PageUp (paged); `+` and `-` zoom in 5-percentage-point steps, `0` fits at 100 %; `m`/Esc bars; `f` fullscreen |
+| Keys | Dispatched through `READER_KEYS` in `public/keys.js`, which also feeds Settings → Keyboard shortcuts and the reader's `?` list. Arrows follow the direction; Space/PageDown/PageUp (paged); `+` and `-` zoom in 5-percentage-point steps, `0` fits at 100 %; `m` saves a moment; `i`/Esc bars; `f` fullscreen; `?` shortcuts |
 
 **Bars:**
 - Shown on open.
 - Hidden on the first page turn or after 100 px of scrolling. The first automatic hide (per device, once for Flow and once for Page/Book) shows a hint on how to get them back.
-- **Never shown by scrolling**, only by a tap beside the pages or in the middle of a page (or `m`). Showing them stops a running smooth scroll, so it can't hide them again right away.
+- **Never shown by scrolling**, only by a tap beside the pages or in the middle of a page (or `i`). Showing them stops a running smooth scroll, so it can't hide them again right away.
 - The top bar has the chapter picker (every chapter, grouped by book, ✓ = read).
 
 **Loading:**
@@ -352,6 +359,8 @@ mode       = adapt && intended ∉ compatible ? compatible[0] : intended
 - Pulses are sent at most every 10 seconds and on pause/page exit. The server validates the manga/chapter/version and page indices, de-duplicates `(session, seq)`, clamps time to server-observed intervals and stores compact page ranges separately from ordinary progress.
 - The bottom toolbar chip shows active time and the current state; its panel adds pass time, verified pages, predominant input and loading wait.
 
+**Moments** (`public/moments.js`): the top bar's bookmark button (or `m`) opens a sheet for the page(s) on screen: in Flow the page at the reading line, in Book the spread. A rectangle dragged over the preview keeps only that region; a region inside one page of a spread saves that page alone. Exactly one category is required. The button is filled when the page already has a moment. The manga page shows the user's moments as a strip of crops (sort by story or by date saved, category filters from five moments), with a viewer to step through them, edit, delete or open the reader at `read.html?…&p=<page index>`. Crops position the full page images inside a clipping box; nothing is generated on the server.
+
 **Zoom persistence:** per mode key (`flow`, `page`, `book`, `strip`), saved 800 ms after the last change.
 
 ## 8. Deployment