feat: git hygiene (branch/preview reaping + cleanup sweep) and panel charts; work sessions under Git (#548)

* feat(panel): session-start, 7d overview spend, and 30d business spend charts

* feat(panel): surface work sessions as a Git page tab (route was orphaned)

* feat(git): reap spent task branches and render previews at lifecycle chokepoints; guarded stale-branch sweep

* feat(panel): stale-branch cleanup button on the Git page

* fix(git,panel): cursor-resumable sweep, force-delete spent refs, local filter state

* docs(map,rag): branch/preview reaping, cleanup sweep, git-tab work sessions, wave-2 charts

---------

Co-authored-by: Renn F <rennf93@users.noreply.github.com>

tests/unit/services/test_workspace_worktree_lifecycle.py

@@ -485,3 +485,89 @@ async def test_self_heal_recovers_clone_root_left_on_task_branch(clone: Path) ->
     assert (wt / ".git").is_file()
     assert _git(wt, "rev-parse", "--abbrev-ref", "HEAD").strip() == branch
     assert _git(clone, "rev-parse", "--abbrev-ref", "HEAD").strip() == "main"
+
+
+# ---------------------------------------------------------------------------
+# delete_local_branch — cleans up the branch ref remove_worktree leaves behind
+# (worktree removal never deletes refs/heads/{branch}; every claimed task
+# leaked a permanent local branch ref until this).
+# ---------------------------------------------------------------------------
+
+
+async def test_delete_local_branch_skips_default_branches(clone: Path) -> None:
+    svc = _service()
+    for branch in ("main", "master", "develop", ""):
+        await svc.delete_local_branch(clone, branch, force=True)
+    # "main" is the clone's actual current branch — still checked out, untouched.
+    assert _git(clone, "rev-parse", "--abbrev-ref", "HEAD").strip() == "main"
+
+
+async def test_delete_local_branch_removes_merged_branch(clone: Path) -> None:
+    svc = _service()
+    _git(clone, "branch", "feature/merged")  # no new commits -> already merged
+    assert _ref_exists(clone, "refs/heads/feature/merged")
+
+    await svc.delete_local_branch(clone, "feature/merged", force=False)
+
+    assert not _ref_exists(clone, "refs/heads/feature/merged")
+
+
+async def test_delete_local_branch_not_merged_skips_without_force(clone: Path) -> None:
+    svc = _service()
+    _git(clone, "checkout", "-b", "feature/unmerged")
+    (clone / "work.txt").write_text("x")
+    _git(clone, "add", "work.txt")
+    _git(clone, "commit", "-m", "unmerged work")
+    _git(clone, "checkout", "main")
+    assert _ref_exists(clone, "refs/heads/feature/unmerged")
+
+    await svc.delete_local_branch(clone, "feature/unmerged", force=False)
+
+    # `-d` refuses an unmerged branch — a clean skip, not an error, ref stays.
+    assert _ref_exists(clone, "refs/heads/feature/unmerged")
+
+
+async def test_delete_local_branch_force_deletes_unmerged(clone: Path) -> None:
+    svc = _service()
+    _git(clone, "checkout", "-b", "feature/unmerged")
+    (clone / "work.txt").write_text("x")
+    _git(clone, "add", "work.txt")
+    _git(clone, "commit", "-m", "unmerged work")
+    _git(clone, "checkout", "main")
+    assert _ref_exists(clone, "refs/heads/feature/unmerged")
+
+    await svc.delete_local_branch(clone, "feature/unmerged", force=True)
+
+    assert not _ref_exists(clone, "refs/heads/feature/unmerged")
+
+
+async def test_delete_local_branch_squash_merged_needs_force(clone: Path) -> None:
+    # RoboCo's default merge method is SQUASH: the branch's commits are never
+    # ancestors of the base afterwards, so `-d` refuses even though the work
+    # fully landed. This is why every terminal-path caller passes force=True —
+    # with -d the completed-task ref would leak forever.
+    svc = _service()
+    _git(clone, "checkout", "-b", "feature/squashed")
+    (clone / "work.txt").write_text("x")
+    _git(clone, "add", "work.txt")
+    _git(clone, "commit", "-m", "feature work")
+    _git(clone, "checkout", "main")
+    _git(clone, "merge", "--squash", "feature/squashed")
+    _git(clone, "commit", "-m", "squash-merge feature")
+    assert (clone / "work.txt").exists()  # the work landed on main
+
+    await svc.delete_local_branch(clone, "feature/squashed", force=False)
+    assert _ref_exists(clone, "refs/heads/feature/squashed")  # -d refused
+
+    await svc.delete_local_branch(clone, "feature/squashed", force=True)
+    assert not _ref_exists(clone, "refs/heads/feature/squashed")
+
+
+async def test_delete_local_branch_missing_branch_is_clean_skip(clone: Path) -> None:
+    svc = _service()
+    await svc.delete_local_branch(
+        clone, "feature/never-existed", force=False
+    )  # no error
+    await svc.delete_local_branch(
+        clone, "feature/never-existed", force=True
+    )  # no error