fix(themes): P2 contrast floors retuned + gated across 9 themes (item 28b done)

18 hex retunes, hue-preserving OKLCH minimal raises except where the
upstream palette defines a canonical value: muted lifted to >= 2.0 on
lumon/white/retro-82/everforest (solved), gruvbox (bg4 #7c6f64), nord
(#616e88, the community comment-brightening), catppuccin-latte
(overlay1 #8c8fa1); text-on-surface >= 4.5 via surface nudges
(ristretto darker, latte lighter); accentAlt >= 3.0 (latte, summer-day
darkened); warn >= 2.5 — the bar's battery tint — darkened on the
light bases (latte, rose-pine dawn, summer-day) and flexoki-light's
four status colors moved to their canonical light-mode 600 series.

check-theme-contrast.py now gates all four adopted floors (7 pairings
x 21 themes, green). good/bad stay audit-only — identity themes sit at
2.0-2.3 there by design, so no exemption mechanism was needed. The
design audit's contrast findings drop 20 -> 1 (miasma's earthy `bad`,
kept as identity). Item 28 slice (b) complete.

Verified: V0, checks.theme-contrast green, flake check green,
re-audit. Rendering is V3 -> HARDWARE-QUEUE eyeball entries.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

agent/BACKLOG.md

@@ -55,8 +55,15 @@ P1s ✓ shipped 2026-07-05 (iteration #32): summer-day + flexoki-light
 subtext/surface/overlay/muted retuned (flexoki to its canonical
 upstream tones), miasma + kanagawa surfaces raised (kanagawa to
 sumiInk4); `subtext/base ≥ 3` now GATED in check-theme-contrast.py
-(all 21 pass). Remaining (b): the P2 floors below + the per-theme
-exemption-list mechanism, then re-audit;
+(all 21 pass). P2s ✓ shipped 2026-07-05 (iteration #33): 18 hex
+retunes across 9 themes (OKLCH hue-preserving minimal raises;
+canonical where upstream defines one — gruvbox bg4, nord #616e88,
+latte overlay1, flexoki 600-series statuses for light mode) and the
+four floors GATED: muted ≥ 2, text/surface ≥ 4.5, accentAlt ≥ 3,
+warn ≥ 2.5 (21×7 pairings green; audit contrast findings 20 → 1 —
+miasma's earthy `bad` stays as identity, good/bad floors stay
+audit-only so no exemption list was needed). Remaining (b): nothing —
+further palette work graduates from slices (c)/(d) findings;
 (c) per-surface polish slices;
 (d) the whole-swap themes brought to the same bar. Visual work is
 V3-bound by nature — screenshots are the review artifact, hardware