v0.3 Phase 4d/4e: palette revision + HC rendering contract

Round-4 feedback (2026-05-15) pulled the system away from the
color.adobe.com primaries toward muted-Material values, separated
brand accent from semantic caution, and reframed high-contrast as a
behavioural rendering contract rather than a palette override.

Two phases land together because the palette revision and the HC
contract are inherently linked — HC mode needs both palette overrides
AND behavioural-token overrides to deliver "different rendering
contract" semantics.

Phase 4d palette revision.

  Dark mode (was wine-aubergine #2A1620, now brown-charcoal #12100E):
    --color-bg            #12100E
    --color-bg-elevated   #1A1713
    --color-bg-card       #211D18
    --color-bg-input      #181510
    --color-sidebar       #0F0E0C
    --color-border        #4A4035
    --color-border-subtle #2C261F

  Brand accent (new — was unset, fell through to v0.2 amber that
  competed with semantic yellow):
    Dark:  --color-accent #C97845 (copper)
    Light: --color-accent #9D5F32 (deeper copper)

  Semantic colours (muted-Material, both modes):
    Dark:  danger #FF8A8A  caution #F2C94C  success #79D59B  info #8AB4F8
    Light: danger #B3261E  caution #7A5D00  success #1B6B3A  info #2457A6

  Light mode work surface (slight paper tone, not pure white):
    --color-bg-card #FFFDF8 (was #FFFFFF)
    --color-bg-elevated #F6F1EA

  Caution fill-only-on-cream rule retires. Ochre #7A5D00 passes AA
  as foreground text on cream under the muted palette, so the single-
  token-per-role convention applies across all four semantic colours
  in both modes.

  LumotiaNotice opacity rebalance:
    Background tint  10% -> 8%
    Outer border     neutral subtle -> role at 40%
    Icon             --color-text -> role colour
    Left bar         role at 100% (unchanged)
    Title / body     --color-text (unchanged)

Phase 4e HC rendering contract.

  Behavioural tokens published alongside palette:
    --grain-opacity            0.06 dark / 0.07 light / 0 in HC
    --shadow-strength          1 default / 0 in HC
    --border-width-control     1px default / 2px in HC
    --focus-ring-width         2px default / 3px in HC
    --panel-radius             8px (reserved for future tightening)

  --quietware-texture-opacity retained as a legacy alias pointing at
  --grain-opacity so Phase 4c slider keeps working through the rename.

  HC palette: pure-black or pure-white base, the other for borders,
  single strong-focus blue #005FCC replaces accent. Brand atmosphere
  steps aside. Selector splits via :not([data-theme="light"]) so
  HC-light and HC-dark variants diverge cleanly.

Verified.

  - npm run check: 0 errors, 0 warnings across 5706 files.
  - Plan doc updated with full before/after tables, behavioural-token
    contract table, and Phase 4c / 4d / 4e log sections.

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

docs/release/v0.3-tactile-quietware.md

@@ -236,6 +236,77 @@ Architectural finding: the v0.2 `SettingsPage.svelte` (2 891 LOC after Phase 4a)
 
 Rationale: phase 4a already delivers "one section at a time" under quietware. Renaming the eight tabs to match the canonical plan (Output / Vocabulary carved out as top-level) is labelling polish, not user-value. Page-skeleton sweep (Phase 5) delivers more visible improvement per LOC. Phase 4b will return after Phase 5 lands.
 
+### Phase 4d — Palette revision per 2026-05-15 round 4 feedback. Landed 2026-05-15.
+
+The color.adobe.com primaries (#FF0700 / #000AFF / #00FF56 / #FFCD00) earned vividness at the cost of brand identity and accent-vs-caution discipline. Round-4 feedback pulled the system back toward muted-Material values with a clear architectural split:
+
+```
+Atmosphere = warm tactile surface
+Status     = red / yellow / green / blue
+Brand      = copper-clay amber accent (--color-accent, distinct from caution)
+Accessibility = high-contrast override is a different rendering contract
+```
+
+Dark mode (revised, brown-charcoal instead of wine-aubergine):
+
+| Token | Before (4c) | After (4d) |
+|---|---|---|
+| `--color-bg` | `#2A1620` | `#12100E` |
+| `--color-bg-elevated` | `#34222B` | `#1A1713` |
+| `--color-bg-card` | `#3E2A33` | `#211D18` |
+| `--color-sidebar` | `#1F0F18` | `#0F0E0C` |
+| `--color-accent` | (unset, fell through to v0.2) | `#C97845` |
+| `--color-danger` | `#FF2A24` | `#FF8A8A` |
+| `--color-caution` | `#FFCD00` | `#F2C94C` |
+| `--color-success` | `#00FF56` | `#79D59B` |
+| `--color-info` | `#7076FF` | `#8AB4F8` |
+
+Light mode (revised, semantic values back to Material AA-friendly hues):
+
+| Token | Before (4c) | After (4d) |
+|---|---|---|
+| `--color-bg-card` | `#FFFFFF` | `#FFFDF8` (warm white) |
+| `--color-bg-elevated` | `#F3EEE6` | `#F6F1EA` |
+| `--color-accent` | (unset) | `#9D5F32` |
+| `--color-danger` | `#C54B1F` | `#B3261E` |
+| `--color-caution` | `#FFCD00` (fill-only) | `#7A5D00` (passes as text) |
+| `--color-success` | `#00852D` | `#1B6B3A` |
+| `--color-info` | `#0047AB` | `#2457A6` |
+
+The "caution fill-only on cream" rule retires under the muted palette. Ochre `#7A5D00` passes AA as foreground text against cream, so the same single-token-per-role convention applies across all four semantic colours in light mode.
+
+LumotiaNotice opacity rebalance:
+
+| Surface | Before | After |
+|---|---|---|
+| Background tint | role at 10% | role at 8% |
+| Outer border | neutral subtle | role at 40% |
+| Left bar | role full | role full (unchanged) |
+| Icon | `--color-text` | role colour |
+| Title / body | `--color-text` | `--color-text` (unchanged) |
+
+### Phase 4e — High-contrast rendering contract. Landed 2026-05-15.
+
+High-contrast is not a colour variant — it's a different rendering contract that the entire UI subscribes to. The tokens block now publishes behavioural variables alongside the palette overrides, so components can opt into the contract by reading them.
+
+Behavioural tokens (defaults + HC values):
+
+| Token | Default | HC |
+|---|---|---|
+| `--grain-opacity` | 0.06 (dark) / 0.07 (light) | 0 |
+| `--shadow-strength` | 1 | 0 |
+| `--border-width-control` | 1px | 2px |
+| `--focus-ring-width` | 2px | 3px |
+| `--panel-radius` | 8px | 8px (unchanged for now) |
+
+`--quietware-texture-opacity` retained as a legacy alias pointing at `--grain-opacity` so Phase 4c controls keep working through the rename.
+
+HC palette tweaks (round-4 feedback):
+
+- **HC light** is now true pure-white background (`#FFFFFF`) + true pure-black text/borders (`#000000`). Brand atmosphere steps aside completely. Single strong-focus blue `#005FCC` replaces the accent.
+- **HC dark** stays pure black `#000000` with white borders, semantic muted hues that read clearly. Matches the v0.3 dark feel but at maximum legibility.
+- Hue-based selectors: `[data-design="quietware"][data-contrast="high"]` matches both base themes; the dark-base variant is scoped via `:not([data-theme="light"])` so light-base HC and dark-base HC can diverge.
+
 ### Phase 4c — Texture-opacity slider + high-contrast toggle. Landed 2026-05-15.
 
 - New static grain overlay defined in `src/design-system/v0.3-quietware-tokens.css`. Fixed-position `body::after`, `mix-blend-mode: overlay`, opacity driven by `--quietware-texture-opacity`. Pattern generated inline via SVG `feTurbulence` (`baseFrequency=0.85`, `numOctaves=2`, `stitchTiles=stitch`). Tile size 240×240, repeated across viewport. `pointer-events: none` so the overlay never intercepts clicks. Active only under `html[data-design="quietware"]` and only on the dark and light modes — high-contrast forces opacity to 0.