feat(git-status): configurable max repositories and git timeout; keep unreadable repos listed

Settings (per device): Git status: max repositories (1-50, default 12) and git timeout (5-120 s, default 30, was a fixed 10). Both go to /git-status and /git-diff as maxRepos / timeout query parameters, clamped server-side (an empty value means the default). A repository whose git status fails stays in the list with the reason instead of being dropped silently, shows as '? N' in the indicator, and the truncation line now names the limit and the setting. The discovery cache is keyed by the limit.

Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01JrzFKEdBLwVfu6ev2ZscJS

.changeset/git-status-limits.md

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+"aicodeman": patch
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+The Git status window's limits are settings now. **Git status: max repositories** (App Settings → Header & Panels → Bottom bar, per device, 1 to 50, default 12) is how many repositories it lists when the session's folder holds several projects, and **Git status: git timeout** (5 to 120 seconds, default 30, was a fixed 10) is how long one git command may run. A repository git could not read (a timeout on a slow network share was the usual cause) used to be dropped without a word, which left a count like "first 11" under a limit of 12; it now stays in the list with the reason, shows as `? N` in the indicator instead of letting it read ✓, and the truncation line reads "Showing the first N of more than N repositories" and points at the setting. `GET /api/sessions/:id/git-status` and `/git-diff` take `maxRepos` and `timeout` (seconds) query parameters, clamped server-side, and the overview reports `repoLimit`.