fix(swaync): palette-safe pairings — text was invisible on summer-day (item 25)

Palette roles aren't uniform: summer-day and flexoki-light use subtext
as text-ON-surface (== base) and surface as a dark chip (== text), so
swaync's @subtext-on-@base body text and @surface/@text buttons were
self-colored (caught on the Latitude).

- body/summary: @text on @base — the one text pairing that passes in
  every palette (survey: worst WCAG ratio 5.18 across all 21 themes;
  subtext/base bottomed at 1.00 twice, muted/base at 1.27).
- hover rows + widget-title buttons: alpha(@text, 0.1) tints —
  contrast by construction; subtext/surface defines dropped.
- NEW checks.theme-contrast (tools/check-theme-contrast.py): asserts
  the hex-on-hex text pairings across themes/*.json, cheap (no VM).

The audit also found the generated waybar/rofi CSS shares the bug
class, live on flexoki-light (no whole-swap) → BACKLOG item 27.

Verified: V0; V1 (checks.theme-contrast builds green, 21 themes;
rendered services.swaync.style has zero @subtext/@surface). Honesty:
NOT visually verified — V3 queued (notify-send on summer-day).

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

agent/HARDWARE-QUEUE.md

@@ -39,6 +39,11 @@ QA machine), the **T14s** (webcam case).
       `home-update` + relogin (or `hyprctl reload`), SUPER+? must open
       the keybindings cheatsheet, whose row still reads `SUPER + ?`
       (not `SUPER + SHIFT + ?`).
+- [ ] **swaync readable on summer-day** (item 25 fix) — on summer-day
+      after `home-update`: `notify-send "title" "body text"` shows
+      readable body text; open the control centre (SUPER+N), hover a
+      notification row and check the Clear button — all text legible
+      (body/buttons now @text on tinted chips, not subtext/surface).
 - [ ] **Keyboard hotplug picker (re-verify after in-flake graduation)** —
       plug an external keyboard post-login, pick a layout in rofi, confirm
       it applies per-device only, persists in `settings.keyboard.devices`,