Slice 7: expose git commands as MCP tools

Add git_fetch/git_pull/git_push/git_commit/git_discard_changes MCP tools as thin adapters over the service (actor=claude), completing 1.7 symmetry so Claude can run the same commands as the right-click menu. git_discard_changes is flagged destructive (confirm first, 1.4). Extended the MCP test with a git_commit round-trip; synced AGENT.md 8.1 tool list.

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

CHANGELOG.md

@@ -188,3 +188,16 @@ Append-only running history of all changes (AGENT.md §9.1). Newest last.
   `cmd/server/main.go`, `components/repo-menu` (new), `components/repo-list`,
   `web/templates/{index,help}.html`.
 - **Next:** expose these git ops as MCP tools so Claude can run them too.
+
+## 2026-09-20 — Slice 7: git commands as MCP tools (§1.7 symmetry)
+- **What:** Added MCP tools `git_fetch`, `git_pull`, `git_push`, `git_commit`,
+  and `git_discard_changes` — thin adapters over the existing service methods
+  (actor=claude), so Claude can run the same commands as the right-click menu.
+  `git_discard_changes`'s description flags it destructive and tells Claude to
+  confirm first (§1.4). Extended the MCP test with a `git_commit` round-trip.
+  Synced AGENT.md §8.1's tool list to the actual names.
+- **Why:** Complete the §1.7 symmetry — every capability reachable from both the
+  GUI and Claude.
+- **Affects:** `internal/mcp` (+test), `AGENT.md` (§8.1).
+- **Note:** the new tools appear in Claude Desktop only after its next restart
+  (tool list cached per connection); network ops still need container git creds.