Slice 6: right-click command menu + git write actions

git boundary: Pull/Push/Commit/DiscardAll (discard is 1.4-destructive). Scanner.RefreshRepo re-scans one repo after a mutation. Service GitFetch/GitPull/GitPush/GitCommit/GitDiscard record a git-* activity event and refresh on success; service.New takes a refresh hook. HTTP POST /api/repo/git. New <repo-menu> overlay with plain-language commands (Get latest/Publish/Check for updates/Save my work/Set active/Ask Claude to switch/Copy path/Discard all changes), summoned by repo-list's repo:contextmenu. Added service test for commit/discard on a temp repo. Verified the menu live for safe commands.

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

internal/git/git.go

@@ -120,6 +120,34 @@ func (c *CLI) Fetch(ctx context.Context, dir string) error {
 	return err
 }
 
+// --- Mutating operations (user/Claude-initiated only; §1.3, §1.4) -----------
+
+// Pull integrates the upstream branch (fetch + merge/ff per repo config).
+func (c *CLI) Pull(ctx context.Context, dir string) (string, error) {
+	return c.run(ctx, dir, "pull")
+}
+
+// Push publishes the current branch to its upstream. Plain push only — never a
+// forced push here (that is a §1.4 action to be added deliberately if ever).
+func (c *CLI) Push(ctx context.Context, dir string) (string, error) {
+	return c.run(ctx, dir, "push")
+}
+
+// Commit stages every change and commits it with message.
+func (c *CLI) Commit(ctx context.Context, dir, message string) (string, error) {
+	if _, err := c.run(ctx, dir, "add", "-A"); err != nil {
+		return "", err
+	}
+	return c.run(ctx, dir, "commit", "-m", message)
+}
+
+// DiscardAll hard-resets tracked files to HEAD, throwing away uncommitted
+// changes. DESTRUCTIVE (§1.4): callers MUST confirm with the user first.
+// Untracked files are left in place.
+func (c *CLI) DiscardAll(ctx context.Context, dir string) (string, error) {
+	return c.run(ctx, dir, "reset", "--hard", "HEAD")
+}
+
 // Branch is a local branch and its upstream, if any.
 type Branch struct {
 	Name     string `json:"name"`