booth/docs/contracts/r2_flow.contract.md

---
contract_version: "0.1-PROPOSED"
status: "PROPOSED 2026-09-23 by design-dev. Ruled by the operator the same day in the `flow` mark on booth-flow-concepts (direction a_b; compare MODE to be built in this arc; voice plain; emblem no), relayed via Miranda → booth-dev, verbatim at docs/rulings/. Compare mode is NOT in this contract: it lands after this one as r3, as a view toggle over the same item record."
module: "booth.app + booth.items + templates (the review flow)"
purpose: "Make the Booth a place where judgment happens rather than a place where files are shown. The operator's bar is 'did anything change when I opened it'. A reskin cannot clear that bar; this contract changes the flow. There are three surfaces and one plumbing change. THE DESK: the index triaged by what needs the operator. THE LIGHTBOX: a booth page with the set on the left and the verdict beside it. THE REVIEW: full size with the judgment on screen, a filmstrip, and seen-tracking. The plumbing is IN-PLACE JUDGMENT: a mark POST that does not reload the page or eject you from full size."
depends_on:
  - "booth.items.booth_items + Item (INV-1: the one resolver). Item gains `ordinal`, derived there and nowhere else."
  - "booth.items.image_chain (the zoom ring). SUPERSEDED for the review route by `review_chain`; image_chain stays importable and unchanged for its existing callers and tests."
  - "booth.app._newest_mtime (THE definition of activity — booth-dev, 2026-09-23). The Desk's 'last activity' reuses it verbatim. The Desk's 'landed since you looked' is a DIFFERENT question and gets a DIFFERENTLY NAMED helper; see INV-5."
  - "booth.app.record_view / VIEW_MARKER (`.viewed`, U4). The Desk reads its mtime to answer 'new since you looked'."
  - "booth.app.hold_read / hold_reason / open_marks (INV-2 of U2: the one openness predicate). 'Needs you' is `open_marks(...)` non-empty, or `hold_reason(...) == \"unreadable\"` (C4); nothing else."
  - "booth.marks.as_dict, set_flag, write_note, answer_pick, delete_mark (the write API, UNCHANGED)."
  - "booth.app._mark_redirect (the 303 landing). Extended with one new `back` value; the existing two landings stay byte-identical."
  - "booth.benches.read_benches, booth.links.parse_link_entries / order_for_display / booth_target (the Desk's side column)."
language: "python + jinja + a little javascript"
complexity: "high"
estimated_loc: 900
confidence: 0.6
used_by:
  - "booth.app.index (the Desk)"
  - "booth.app.booth_view (the lightbox)"
  - "booth.app.booth_view_file (the review)"
  - "booth.app.booth_answer / booth_note / booth_flag / booth_unmark (in-place judgment)"
touches:
  - "booth/items.py (Item.ordinal; review_chain; read_seen/SEEN_FILE)"
  - "booth/app.py (list_booths fields; index sections; booth_view verdict data; booth_view_file review context + record_seen; wants_json + 204; _mark_redirect `back=view`)"
  - "booth/templates/index.html (REWRITTEN as the Desk)"
  - "booth/templates/booth.html (restructured: two panes; the marks panel moves into the verdict aside; tiles carry ordinals; inline group headers)"
  - "booth/templates/view.html (REWRITTEN as the review: stage, rail, filmstrip, tape)"
  - "booth/templates/_marks.html (renders inside the aside; flag list ordered by ordinal)"
  - "booth/templates/base.html (layout CSS; the in-place script)"
  - "booth/templates/doc.html (NOT restructured — a doc keeps its reading page; named because it was checked)"
  - "booth/static/embed.js (NOT TOUCHED — the verbatim path keeps its author's layout; requirement 6)"
  - "tests/test_booth.py (TWO assertions change: L785-786, the kept-lane presence pair. L810-811, the absence pair, survive unchanged. See 'Assertions that change')"
  - "tests/test_flow.py (NEW)"
assumptions:
  - "ONE VIEWER. `.seen` records what has been seen at full size, not WHO saw it. ROADMAP parks 'per-viewer state (who has seen what)' on the one-viewer premise; this contract keeps that premise and does not reopen the parked item."
  - "EVERY JUDGMENT WORKS WITH JAVASCRIPT OFF. Each control stays a plain <form method=post>. The in-place behaviour is additive and falls back to today's 303."
  - "THE VERBATIM PATH IS OUT OF SCOPE. A booth with its own index.html is served as the author wrote it (requirement 6). The Desk links to it; the lightbox never renders for it."
  - "NO THUMBNAILS. Tiles, the filmstrip and the Desk's preview strip use the original files with loading=lazy. Progressive loading stays parked until page weight is measured."
open_questions:
  - "ANSWERED BOOTHS LOSE THEIR HOLD (raised by booth-dev in b46ac02). A booth is held while its question is open, so it becomes sweepable the moment it becomes a decision record. The flow question: should an answered pick hold its booth for a grace period, or should the record live elsewhere? NOT SOLVED HERE, because it is a lifetime-policy change and this contract changes no lifetime rule. Raised separately."
  - "KEY 1–9 TO ANSWER A PICK from the review rail. It appeared in the concept mock. Dropped from this contract: multi-question picks make the mapping ambiguous, and the operator ruled the flow, not the keymap. Parked."
---

# R2 — the review flow: the Desk, the lightbox, the review

## The requirements this answers (from the round-2 README, uncorrected by the operator)

| # | requirement | answered by |
|---|---|---|
| 1 | show me what needs me | the Desk's *needs you* section |
| 2 | picking winners is the main judgment | the lightbox's flag tray; F in the review |
| 3 | flag without losing my place | in-place judgment + `back=view` |
| 4 | position is identity (within the set as it is now — not a durable id) | `Item.ordinal`, printed on every tile |
| 5 | the question stays beside the work | the verdict aside (sticky) |
| 6 | reports keep their author's layout | verbatim path untouched |
| 7 | listening sets are real | `review_chain` includes audio and video |
| 8 | lifetime is not an organising principle (it is still SHOWN as a fact on each row; it no longer GROUPS or SORTS) | the Desk drops the kept/ephemeral lanes |

## Terms used below

- **Reticle**: the SVOS selection mark in base.html — four corner brackets drawn
  inside a box. It marks the one current or selected thing and nothing else.
- **Tape**: a row of small segments, one per item in the review ring, each
  showing *seen*, *flagged* or *current*.
- **Stage**: the area of the review page where the artifact itself renders.
- **All Booth state files are dotfiles.** That covers `.marks.json`
  (MARKS_FILE), `.viewed`, `.blurred`, `.seen`, `.forever`, `.pins`,
  `.booth.json` and every `*.lock`. "Non-dot entries" means the posted content
  and nothing the Booth or the operator wrote.

## Components

### C1 — `Item.ordinal` (items.py)

`ordinal: int` is the item's 1-based position in `booth_items(booth)`, i.e. in
`sorted(rel)` order over **all** items. It is assigned in the resolver loop, so
no route derives it.

- `ordinal` is **appended** as the dataclass's last field, never inserted.
  Mid-dataclass insertion is a positional-construction break, and `group` has
  already had that conversation.
- The resolver's `quote()` guard on non-UTF-8 names stays exactly as it is. It
  looks like a stray `try` around a discarded result, but it is what keeps one
  0xff filename from taking down the index for every booth.
- An item skipped by that guard takes no ordinal, so ordinals stay contiguous
  over the items that render.

- **A filter never renumbers.** Under `?filter=flagged` a tile still shows the
  number it has in the whole set. That is the point: "#07" is a property of the
  item, not of the view.
- **A new file renumbers everything after it.** That is honest, and it matches
  the order: the operator's positional references are to the set as it is now.

### C2 — `review_chain` and `.seen` (items.py, app.py)

- **`review_chain(items)`**: the rels of items whose kind is image, video or
  audio, in item order. ONE LINE: *the item order filtered to media.* It
  replaces `image_chain` as the review route's prev/next ring.
  - It is a **declared change** to the zoom-ring rule. Today's ring is images
    only. A booth mixing images and audio now rings through both, in set order.
  - `image_chain` stays for its callers and tests.
- **`SEEN_FILE = ".seen"`**: one rel per line, same shape as `.blurred`.
  - Written by `record_seen(booth, rel)` from the review route, below the 404s
    and gated on the item record — the same gate `record_view` has.
  - Each write rewrites the whole file: the previous set plus `rel`, minus
    rels no longer in `booth_items`, sorted. It is deduplicated and pruned, so
    it never grows past the booth's item count.
  - Atomic replace, per the Booth's CLAUDE.md invariant 5 ("sidecar writes are
    atomic"), not this contract's INV-5.
  - Seen is keyed by rel. A file replaced at the same path stays seen; a
    deleted file drops out at the next write, and every count below
    intersects with the current `review_chain`.
  - **The review route ALSO calls `record_view` (existing U4 behaviour,
    unchanged).** So reviewing a booth at full size refreshes "you looked" for
    the Desk exactly as opening its grid does. `.viewed` and `.seen` never
    disagree about whether you looked at the booth; `.seen` only adds WHICH
    items.
  - NEVER RAISES, like `record_view`: failing to record a look costs the
    marker, not the page.
- `read_seen(booth) -> set[str]` is lenient, like `read_blurred`.
- **Seen is UI state, not judgment.** It is not exposed in `marks.json` and it
  holds nothing.
  - It adds no lifetime RULE. Being a dotfile, its write does move
    `_newest_mtime`. So does the `.viewed` write on the same request, so a
    review page ages a booth exactly as it does today.

### C3 — in-place judgment (app.py, base.html)

**`wants_json(request) -> bool`** is True **only** when the `Accept` header,
split on commas with parameters stripped, contains the exact media type
`application/json`.

- Absent, empty, `*/*` or `application/*` → False.
- Any header that fails to parse → False.
- **It fails toward the 303.**

The four mark routes (`/answer`, `/note`, `/flag`, `/unmark`) perform the same
write as today, then:

- `wants_json` → **204 No Content**.
- otherwise → today's `_mark_redirect(...)`, **byte-identical**: same status,
  same `Location`, same body.

**`back=view`** is a new landing for `_mark_redirect`, carried by the review
route's forms together with `f=<rel>`. It lands on
`/b/<name>/view?f=<quote(rel)>#rail`. This fixes the JS-off bounce too:
today's zoom flag form carries no `back`, so it lands on the gallery.

- `back=view` lands on the review only when `f` names an item in
  `review_chain`, i.e. a media item. For anything else (a doc, a missing rel,
  an empty `f`) the landing falls back to the booth page, exactly as a form
  with no `back` does today. `doc.html` carries no forms, so no shipped page
  sends `back=view` with a doc.
- The URL is built server-side from `name` + `quote(f)`, never echoed, so this
  is not an open redirect.

**The client**: one small script in base.html, bound to forms marked
`data-inplace`.

1. POST the form with `Accept: application/json`.
2. On 204, GET the current URL and replace **every** element carrying
   `data-region="<id>"` with the same-id element from the response.
   - The rule is "every region whose content can depend on marks is a
     region". On the lightbox that means the verdict aside, each tile, and the
     rail (its filter counts change when you flag). On the review it means the
     rail, the filmstrip and the tape.
   - The stage is never a region: replacing it would restart a playing video
     or audio track.
   - A region absent from the response is left alone and never deleted.
3. **The script never re-POSTs.** A retry after a lost response would re-apply
   the judgment: a duplicate note, or a re-dated answer.
   - On a non-204 HTTP response, or a network failure, it writes a fixed
     message into the page's server-rendered status element
     (`data-region="status"`, via textContent), then reloads the page with a
     GET, so what you see is the server's truth.
   - The one case where a non-JS submit happens is a script that cannot run at
     all. That is the plain form.

**The server renders every state; the script only places it.** This is U3's
rule — a second renderer in JavaScript would be the same bug in a new language.

### C4 — the Desk (index.html, app.index, list_booths)

`list_booths` gains five fields, all read in the one pass it already makes:

- **`open_since`**: the `created` of the OLDEST open pick in the booth, or
  None. Computed via `open_marks`, INV-2.
  - `Mark.created` is a STRING. It is parsed with `datetime.fromisoformat`,
    never compared lexically: two ISO stamps with different offsets, or a
    legacy-import stamp, sort wrong as text.
  - An unparseable stamp sorts AFTER every parseable one, and name breaks the
    tie.
- **`flags`**: the count of flag marks, shown on every Desk row that has any.
- **`landed_at`**: the newest mtime among the booth's NON-DOT entries — its
  content. **Deliberately not `_newest_mtime`** (INV-5).
- **`viewed_at`**: the mtime of `.viewed`, or None.
- **`preview`**: up to 4 image items as `(url, blurred)`, first four in item
  order. A blurred one renders blurred, the same rule as the cover.
  - A booth with no images (an audio set, a report) shows today's kind
    placeholder instead (`♪ audio`, `▦ page`, `▶ video`, `◆ files`).
  - These are the original files displayed small with `loading=lazy`. No
    thumbnail is GENERATED anywhere in R2; see Out of scope.

**The index renders three sections, always in this order:**

1. **Needs you** — `marks_open > 0`, **or** `hold == "unreadable"`.
   - `marks_open` counts `open_marks(...)`, which only ever returns PICKS. A
     booth whose marks are only flags or notes is the operator's own judgment,
     not a question to them, so it is NOT here.
   - A damaged `.marks.json` holds its booth but is not open by `open_marks`
     (errored picks are not open). Somebody has to fix it, so it must not hide
     in 'everything else'. It renders with the existing "marks unreadable"
     lifetime line.
   - Ordered by `(open_since, name)`, oldest question first. Unreadable booths
     have no `open_since` and sort after every booth that has one.
2. **New since you looked** — `not in_needs_you and (viewed_at is None or
   landed_at > viewed_at)`. Ordered by `(-landed_at, name)`, newest first.
3. **Everything else** — ordered by `(-mtime, name)`, where `mtime` is today's
   `_newest_mtime`: last activity first.
   - Flagging or viewing a booth moves it up this section. That is intended:
     it is activity. It never moves the booth into (2), because (2) reads
     `landed_at` (INV-5).

The side column holds:

- **Benches**: `read_benches(data_dir)`, non-retired, in the registry's
  existing order. Its error return renders as an error line, never as an empty
  list. This is the booth page's rule: damaged and absent must not render the
  same.
- **Bookmarks** come from the board the CLI writes: the booth named by
  `BOOTH_LINKS_BOARD`, default `links`. They are read through the same
  never-raising path as `_board_rows`, which gets factored so both callers
  share it.
  - Shown: rows that are not booth URLs (`booth_target(url) is None`).
  - Order: pinned first, then newest (`order_for_display`).
  - Capped at 8, with a link to the full board.
- **Pickup**: the existing upload form, unchanged, moved from the page head.

**An empty section does not render** — no heading, no box. This is the
load-bearing negative half of the kept-lane pair it replaces
(`'class="grid kept-grid"' not in html`), carried forward into test_flow.py as
a pair: present when it has rows, absent when it has none. It applies to each
of the three sections and to the Benches and Bookmarks panels.

The kept/ephemeral lanes are **removed**: 23 of 24 live booths are kept, so the
lanes sort nothing. Kept status and the lifetime line (`_lifetime.html`,
unchanged) remain on every row.

### C5 — the lightbox (booth.html, booth_view)

- **Layout.** Two panes on a gallery booth: the set on the left, the
  **verdict aside** on the right (`position:sticky`, `data-region="verdict"`).
  Under 1000px the aside stacks above the set, with its flags and notes
  collapsed as `<details>`, which needs no script.
- **Board booths are unchanged.** Anything with `links.md` keeps today's
  single column.
- **The aside holds, top to bottom:**
  1. open picks (the existing `_marks.html` pick rendering);
  2. the flag tray;
  3. notes;
  4. the booth-note form.
- **The flag tray is ordered by ORDINAL** — a declared change from the marks
  panel's `(created, id)`. It shows each flagged item's original file
  displayed small (no generated thumbnail), blurred if the item is blurred,
  with its #.
  The order is total with no tie-break, because rels are unique.
- **The rail stays.** Same element, same `.rail` class (booth.html's cursor
  and base.html's `--rail-h` script both read it), same filter hrefs, same
  group anchors. When `rail.groups` is non-empty, the grid additionally
  renders an inline group header before each group's first tile. It is a
  `<div>` spanning the grid, never a `figure.item`, so the keyboard and the
  order check are blind to it by construction.
- **Every tile shows `#NN`** (its ordinal, zero-padded to the set's width).
  Each tile is `data-region="item-<url>"`, so the in-place script can replace
  exactly the tile it flagged.

### C6 — the review (view.html, booth_view_file)

This applies to image, video and audio items. Docs keep `doc.html`.

- **The stage**: the artifact at fit size, with a 1:1 toggle for images ONLY.
  - The toggle and its script are rendered and bound only when the stage is
    an `<img>`.
  - The toggle is a JS-only VIEWING convenience, as it is today: the button
    starts hidden and the script shows it. With scripts off the image shows at
    fit size, and no judgment depends on the toggle (INV-3).
  - Video and audio get their native controls and no toggle. A toggle that
    renders on audio and silently no-ops (today's script binds
    `getElementById('vimg')`) is the failure this names.
- **The rail** (`data-region="rail"`) holds:
  - the item's ordinal `#NN` (its number in the whole set, the same number
    its tile shows);
  - `K of M`, where K is its position in `review_chain` and M is the length
    of `review_chain`. The tape's "N of M seen" uses the SAME M, and N counts
    `.seen` ∩ `review_chain`;
  - its position within its group, when the booth has groups;
  - the caption;
  - the flag form (`back=view`);
  - notes and the add-note form (`back=view`);
  - any open pick TARGETING this item, answerable here (`back=view`);
  - the booth's other open picks as a count and a link.
- **The filmstrip** is `review_chain` in order, with ordinals, flagged frames
  underlined and the current frame in the reticle.
- **The tape** (B's device) is one segment per `review_chain` item: seen /
  flagged / current, plus "N of M seen".
- **The end of the set** is not a separate page. On the last ring item the
  rail adds a summary block: seen count, flag tray, and every open booth-level
  pick answerable in place.
- **Keys** (additive). **Every** key here, new and old, is ignored while focus
  is in an `input`, `textarea`, `select` or `contenteditable`, the same
  `isEditable` guard view.html carries today, so F never fires mid-note:

  | key | action |
  |---|---|
  | ← → and Space | move |
  | F | flag |
  | N | focus the note |
  | Esc | back to the grid, at `#item-<url>` so the grid scrolls to where you were |

### C7 — copy and brand (the two rulings that are not layout)

- **Voice: plain and direct** (ruling `voice=plain`). Every NEW string R2
  introduces says what it means, with no villainy and no jokes. Existing
  strings are unchanged unless their surface is rewritten.
- **No SVS emblem** anywhere in the Booth's chrome (ruling `emblem=no`). The
  brand dot and the reticle favicon from the SVOS retheme stay.

## Invariants

- **INV-1 — one resolver.** `ordinal` is set in `booth_items`. No route computes
  a position.
- **INV-2 — order, stated.** Each ordered surface has a one-line rule:

  | surface | rule |
  |---|---|
  | items | `sorted(rel)` |
  | ordinals | position in that |
  | review ring | that, filtered to media |
  | filmstrip, tape | the review ring |
  | flag tray | by ordinal |
  | Desk sections | fixed: needs → new → everything |
  | needs you | `(open_since, name)` |
  | new since you looked | `(-landed_at, name)` |
  | everything else | `(-mtime, name)` |
  | bookmarks | `order_for_display` |

  The notes list keeps `(created, id)`.
- **INV-3 — JS-off parity.** Every judgment, filter and jump works with
  scripts disabled. The only JS-only affordances are:
  - the keys;
  - the in-place swap;
  - the image 1:1 toggle (a viewing convenience, unchanged from today);
  - the existing copy buttons and blur reveal.

  The narrow-screen collapse is `<details>` and needs no script.
- **INV-4 — 303 byte-identity, for every request shape that existed before
  R2.**
  - For a request where `wants_json` is False and `back` is absent or
    `marks`, each mark route's response (status, headers, body) is
    byte-identical to its pre-R2 response.
  - `back=view` is a NEW request shape with no pre-R2 counterpart. Its landing
    is specified in C3 and is the one declared exception.
- **INV-5 — two named clocks.**
  - `mtime` / `_newest_mtime`: activity. It includes dotfiles and excludes
    locks, and it feeds lifetime and 'everything else'.
  - `landed_at`: content only (non-dot entries), and it feeds 'new since you
    looked'.
  - Never the one where the other is meant: a mark or a view is not new
    content, and new content is not the only activity.
- **INV-6 — no second renderer.** The in-place script inserts server-rendered
  HTML and builds none.
- **INV-7 — autoescape.** No `|safe` on any booth name, item name, caption,
  why or mark text. The flag tray and filmstrip render names through the same
  escaping path as the grid.
- **INV-8 — blur honesty.** A blurred item stays blurred on every new surface:
  the Desk preview strip, the flag tray, the filmstrip and the review stage.
  Reveal stays per-BROWSER and client-side (nothing persisted). Copy keeps admitting it is cosmetic.

## Assertions that change (declared before the code, per CLAUDE.md)

| test | today | after R2 | why |
|---|---|---|---|
| test_booth.py L785 | `class="grid kept-grid"` present when a booth is kept | absent; the kept booth appears in its Desk section with the `kept` lifetime line | requirement 8: the lanes sort nothing |
| test_booth.py L786 | `class="card card-kept"` present | replaced by the row carrying `data-kept="1"` | same |
| test_booth.py L810-811 | lane absent when nothing is kept | these two SURVIVE unchanged (they assert absence and stay true) | — |

Every other existing assertion is expected to survive, and one of the TDD
slices is "the whole suite green before any new test". Named because they were
checked:

- the `vnav vprev` / `vnav vnext` anchors (test_booth L569-591 and
  test_navigation L337) keep their classes and hrefs;
- `Wipe now` stays in the booth header;
- `class="boothhead"` stays.

## Out of scope

- Compare (r3).
- Thumbnails.
- 1–9 answer keys.
- Lifetime policy for answered picks.
- The verbatim path. A verbatim booth's media items remain reachable at
  `view?f=` by URL, as today, and nothing in the verbatim page links there.
- The link-board page (`/b/links/`) beyond CSS.