feat(coord): add todos system with per-user/machine/project scoping

New coord_todos table and API endpoints (GET/POST/PUT/DELETE /api/coord/todos)
supporting manual and auto-created items, sub-tasks via parent_id, and inclusive
for_user/for_machine filters (OR-null) for sync/save display. sync.sh Phase 7
now shows pending todos grouped by project after every sync. CLAUDE.md documents
auto-creation behavior for unresolved follow-up. Web/email pricing doc updated:
block time rate clarified, INKY reference removed, dates updated.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

api/models/__init__.py

@@ -10,6 +10,7 @@ from api.models.coord_work_item import CoordWorkItem
 from api.models.coord_session_lock import CoordSessionLock
 from api.models.coord_component_state import CoordComponentState
 from api.models.coord_message import CoordMessage
+from api.models.coord_todo import CoordTodo
 from api.models.backup_log import BackupLog
 from api.models.base import Base, TimestampMixin, UUIDMixin
 from api.models.billable_time import BillableTime
@@ -57,6 +58,7 @@ __all__ = [
     "CoordSessionLock",
     "CoordComponentState",
     "CoordMessage",
+    "CoordTodo",
     "BackupLog",
     "Base",
     "BillableTime",