feat(repos): add an "Initialize mise" option to the add-repo step

Some repos an operator wants to manage don't yet define the `.mise.toml`
`[tasks.test]` task the spawn gate hard-requires — a chicken-and-egg,
since you can't run an agent to author that file without it. This adds a
one-click bootstrap.

Ticking "Initialize mise" on the add step enqueues a `mise_init` command
after the clone. The worker launches a dedicated agent that detects the
repo's stack, writes a `.mise.toml` with a canonical `[tasks.test]` task,
and commits + pushes it. That agent runs with the test-task gate off
(creating the task is the point) and a `HANDLER_MISE_INIT` marker on, so
its hooks enforce a bootstrap contract instead of the normal test gate:

- Stop hook blocks the turn until `.mise.toml` defines `[tasks.test]` and
  the change is committed (clean tree) and pushed (no commits ahead of an
  upstream) — so claude cannot end before the work has actually landed.
- git-push hook lets the bootstrap push through, skipping the test/build
  gate (there may be no working suite yet) so the file reaches the remote.

Backend: `mise_init` command type (+ migration 0006), a shared
`control.mise` helper for the test-task check, `spawn(require_tests=,
mise_init=)`, gitops `is_clean`/`ahead_count`, and `init_mise` on the
project-create API (only acts when a git remote exists to push to).
Frontend: the checkbox, plumbed through the store, following the launch.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01BxKY28XKCM6o4ag3nmaVsZ

tests/test_control_spawn.py

@@ -68,6 +68,32 @@ def test_spawn_creates_agent_settings_and_session(env, fake_tmux):
     assert call["env"]["DATABASE_URL"] == env["url"]
 
 
+def test_spawn_mise_init_skips_test_gate_and_marks_env(env, fake_tmux):
+    # A repo with no .mise.toml at all: the normal gate would refuse, but the mise-init
+    # bootstrap agent must launch anyway (creating that file is its whole job).
+    root = env["tmp"] / "proj"
+    root.mkdir(parents=True, exist_ok=True)
+    _register_project(root)
+
+    agent = spawn.spawn("proj", "mise-init", require_tests=False, mise_init=True)
+
+    with get_engine().begin() as conn:
+        assert repo.get_agent_by_name(conn, "proj", "mise-init")["id"] == agent["id"]
+    # The launched session carries HANDLER_MISE_INIT so its hooks enforce commit + push.
+    call = fake_tmux["calls"]["new_session"][0]
+    assert call["env"]["HANDLER_MISE_INIT"] == "1"
+
+
+def test_spawn_still_gates_without_mise_init_flag(env, fake_tmux):
+    root = env["tmp"] / "proj"
+    root.mkdir(parents=True, exist_ok=True)
+    _register_project(root)
+    # require_tests defaults on, so a normal spawn against a mise-less repo still refuses.
+    with pytest.raises(spawn.SpawnError, match="no .mise.toml"):
+        spawn.spawn("proj", "api")
+    assert fake_tmux["calls"]["new_session"] == []
+
+
 def test_kill_sets_done_and_kills_session(env, fake_tmux):
     root = env["tmp"] / "proj"
     _write_mise(root, with_test=True)