Slice 13: repo search + filtering (+ no-cache dev assets)

<repo-list> gains a search box (name/path) and Dirty/Ahead-behind filter chips with an N-of-M count; filtering is client-side and the state persists in localStorage (gitmanager.repolist.filters, §4). Refresh/selection re-apply filters. cmd/server sends Cache-Control: no-cache for /components and /static so hot-reloaded asset edits show on reload. Server-verified (curl); live click-through pending an unresponsive browser pane.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

CHANGELOG.md

@@ -260,3 +260,16 @@ Append-only running history of all changes (AGENT.md §9.1). Newest last.
 - **Why:** Immediate, legible feedback for the non-expert audience (§6 polish).
 - **Affects:** `components/toast-host` (new), `components/repo-menu`,
   `components/pr-list`, `web/templates/index.html`.
+
+## 2026-09-20 — Slice 13: repo search + filtering
+- **What:** `<repo-list>` gained a search box (name/path, case-insensitive) and
+  "Dirty" / "Ahead/behind" filter chips with a "N of M" count. Filtering is
+  client-side over the fetched list; state persists per-viewer in
+  `localStorage["gitmanager.repolist.filters"]` (§4). Refresh/selection re-apply
+  the active filters.
+- **Why:** Keep the dashboard usable as the number of repos grows.
+- **Affects:** `components/repo-list`, `web/templates/help.html`.
+- **Dev-server tweak:** `cmd/server` now sends `Cache-Control: no-cache` for
+  `/components` and `/static` so browsers revalidate assets on reload (cached ES
+  modules were defeating hot reload). Server serves the new component (curl-
+  verified); live click-through pending (browser pane was unresponsive).