fix: subreddit badge fill, tagline 'to' cleanup, and comments li spacing

- Default subreddit badge background from transparent to opaque fill
  (light: #fde8e0, dark: #3d2518) so page highlights don't bleed through
- Remove lingering "to" text node from tagline when subreddit is hidden
- Hide the <li> wrapping the comments link (not just the <a>) to
  eliminate leftover whitespace in the flat-list
- Simplify popup: subreddit bg fields are now color pickers (no longer
  need transparent text-input workaround)

Co-authored-by: Cursor <cursoragent@cursor.com>

chat-summaries/2026-08-26_14-07-summary.md

@@ -0,0 +1,40 @@
+# Firefox Reddit Tweaks Extension — Full Build
+
+**Date:** 2026-08-26
+
+## Task
+
+Design and implement a Firefox extension that reskins old Reddit post listings by moving subreddit names and comment counts into styled badge elements above each post title.
+
+## Process
+
+1. **Brainstorming** — Explored requirements via mockup analysis and clarifying questions (old Reddit only, all pages, user-configurable colors with per-subreddit overrides, light/dark mode)
+2. **Design spec** — Written, self-reviewed, committed (`docs/superpowers/specs/2026-08-26-reddit-badge-tweaks-design.md`)
+3. **Adversarial review** — Found and resolved 9 gaps (div.thing selector, shared module loading, FOUC, teardown logic, dark mode timing, observer target, comment text parsing, permissions, storage quotas)
+4. **Implementation plan** — 4 tasks, committed (`docs/superpowers/plans/2026-08-26-reddit-badge-tweaks.md`)
+5. **Subagent-driven execution** — Each task dispatched to implementer, then reviewed:
+   - Task 1: Manifest + settings module + icons
+   - Task 2: Badge CSS with FOUC prevention
+   - Task 3: Badge DOM manipulation with MutationObservers
+   - Task 4: Settings popup UI
+6. **Final review** — Found 1 Critical (disabled-state hides UI), 2 Important (shallow merge, fire-and-forget saves). All fixed.
+
+## Files Created
+
+- `manifest.json` — Extension manifest (MV2)
+- `lib/settings.js` — Settings read/write module
+- `content/styles/badges.css` — Badge styling + FOUC prevention
+- `content/tweaks/badges.js` — DOM manipulation + observers
+- `content/main.js` — Entry point + storage listener
+- `popup/popup.html` — Settings UI
+- `popup/popup.css` — Settings styling
+- `popup/popup.js` — Settings logic
+- `icons/icon-48.png`, `icons/icon-96.png` — Placeholder icons
+
+## Follow-up Items
+
+- Manual QA in Firefox via `about:debugging` (test checklist in spec, items 1-15)
+- Replace placeholder icons with proper design
+- Optional: extract subreddit name helper for DRY
+- Optional: add error handling to `loadSettings()` / `init()`
+- Optional: support transparent backgrounds in per-subreddit overrides