fix(as-S2): legibility — nothing fades, labels 11px, sentences 12px

From the anti-slop run (design-dev, 2026-09-28). Faded is not legible:
opacity divides whatever contrast a line had.

- Review arrows: the chip under the thin chevron is 82% dense, not 60%;
  the glyph now clears 7:1 over a white stage by colour (was 3.84:1), and
  reads at pixel level where the detector sampled a 2.9:1 median.
- Filmstrip numbers, the marks' state stamp and the inline ask's state tag
  are labels at 11px (were 9.5 / 10.5 / 10.5px).
- The Desk's section rules, the board note and the bench note are
  sentences at 12px.
- Retired benches: no opacity; the link and URL take --text-muted.
- Embed chrome: answered-ask details and the "recorded:" line inherit the
  host's text colour at full strength (the embed cannot know the host's
  palette); the notes placeholder inherits it at 75%, not the UA grey.

Folded from the heid bug-hunt: the embed's ask title no longer fades
either (Q9), and the legibility claims are also held on the browser's
COMPUTED style (tests/test_antislop_s2_browser.py): a stylesheet grep
cannot see a later rule in the cascade (font-size:1px, color:transparent,
filter:grayscale, a placeholder at opacity:0); the browser can.

Folded after the first gate run: the flagged tray's number, the tile's
"flagged" stamp and compare's A/B badge were still under the 11px label
floor; they take --size-micro too. Two film-number rows are re-anchored
on the .film-ord selector: the tray's line is now identical to it, and
the runner mutates the first match.

Contract: as_antislop S2. Falsifiers: antislop.toml 34/34 proved (S1+S2);
all 12 tables 314/314 proved on this tree.

docs/contracts/as_antislop.contract.md

@@ -12,6 +12,7 @@ complexity: "low per slice"
 touches:
   - "booth/app.py (filters)"
   - "booth/templates/_marks.html, _ask_inline.html, booth.html (S1)"
+  - "booth/templates/base.html, view.html; booth/static/embed.js (S2)"
   - "tests/test_antislop.py; tests/mutations/antislop.toml"
 assumptions:
   - "ONE VIEWER, on this box: local time is the operator's time (US Pacific), as the existing date filters already assume."
@@ -59,10 +60,38 @@ The run found that the Booth is sound on desktop and has a set of problems a vie
 
 **Out of S1:** the CLI keeps writing its board rows as it does today. The board is a multi-writer file other sessions parse, so its storage form is not changed; `clock` reads both forms.
 
-## S2 to S6
+## S2 — legibility
 
-These are added to this contract as each slice is staged, in the order of the report's plan:
-- S2, legibility;
+**The rule.**
+- Faded is not legible. A de-emphasised line is quieter by size, weight or a muted colour, never by `opacity`: opacity takes whatever contrast the line had and divides it.
+- Labels are 11px or larger (`--size-micro`).
+- A sentence-like line is 12px or larger (`--size-caption`).
+
+- **Review arrows on a light stage.** The ‹ › glyph sits on a translucent dark chip. At 60% the chip let a light stage through, and the thin glyph sampled at a median of 2.9:1 (the detector's pixel method; by colour it is about 4:1). The chip is at least 80% dense, so the glyph clears 7:1 over the lightest stage by colour, and reads at pixel level too.
+  - *Falsifiable:* a chip back at 60% fails `test_review_arrows_hold_over_a_white_stage`, which composites the glyph over the chip over white.
+- **The filmstrip numbers are labels:** `--size-micro`, not 9.5px.
+  - *Falsifiable:* 9.5px fails `test_film_numbers_meet_the_label_floor`.
+- **Retired benches keep their contrast.** The row carries no `opacity`. The link and URL take `--text-muted`, and the state word says RETIRED.
+  - *Falsifiable:* `opacity:.5` back on the row fails `test_retired_benches_are_not_faded`.
+- **The marks' state stamp** (`? open`, `✓ answered`) is a label at `--size-micro`, not 10.5px.
+  - *Falsifiable:* `test_mark_state_meets_the_label_floor`.
+- **The inline ask's state tag** (the embed chrome's `✓ answered 28 Sep 0848`) is a label at 11px, not 10.5px. S1's `<time>` made the detector measure it on its own.
+  - *Falsifiable:* `test_the_ask_tag_meets_the_label_floor`.
+- **Hint lines are sentences:**
+  - the Desk's section rules (`.desk-rule`: "oldest question first", "running things");
+  - the board's note;
+  - the bench head's note.
+
+  They sit at `--size-caption`.
+  - *Falsifiable:* `test_hint_lines_meet_the_sentence_floor`.
+- **The embed chrome fades nothing.** An answered ask's option details and its "recorded:" line inherit the host page's own text colour, with no `opacity`, so they carry the host's contrast whatever the host is. The embed cannot know the host's palette; its own palette follows the Booth theme, not the report. The notes field's placeholder inherits that colour at 75%, where it had been the browser's grey (3.5 to 4.3:1 on dark).
+  - *Falsifiable:* `test_embed_fades_nothing`.
+- **Folded after the first gate run:** three more labels were below the 11px floor, and they are now `--size-micro` like the rest. They are the flagged tray's number (10px), the tile's "flagged" stamp (10.5px) and compare's A/B badge (9.5px). The report's list had named only the film numbers. *Falsifiable:* the same computed-style test, and three more rows.
+- **Folded from the heid bug-hunt.** The embed's ask title no longer fades either (`opacity:.62` on `.bk-ask-title` contradicted "nothing fades", Q9). The claims above are also held on the browser's computed style (`tests/test_antislop_s2_browser.py`): a stylesheet grep cannot see a later rule in the cascade (`font-size:1px`, `color:transparent`, `filter:grayscale`, a placeholder at `opacity:0`), and the browser can.
+
+## S3 to S6
+
+These are added as each slice is staged:
 - S3, phone layouts;
 - S4, reading measure;
 - S5, interaction and screen readers;