Implement linear task chains and recurring maintenance buckets

Backend, web timeline, and Android widget wiring for the last two
unimplemented items from doot-future-task-scheduling-ideas.

Chains: task_chains table + chain_id/chain_position/chain_unlocked on
native_tasks (migration 026), WIP-limit-1 advancement hooked into
CompleteNativeTask, locked tasks excluded from all date-based queries,
5 new /api/widget/chains* endpoints, an N/M position badge on web and
Android widget rows.

Buckets: maintenance_buckets table + bucket_id/bucket_state/
bucket_last_active_at on native_tasks (migration 027),
staleness-then-priority selection scoring, a new RunBucketCycleCheck
scheduler loop, 5 new endpoints including the distinct Defer action, a
Defer button on web and Android widget rows.

Also corrected stale "not yet approved" status headers on the two
already-shipped specs this work depended on (labels/projects, budgets/
availability) -- their headers were never updated after implementation.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01EZ7ikw2ukGJFTHE3bJS7zL

1 files changed, 29 insertions, 1 deletions

diff --git a/internal/store/native_tasks_test.go b/internal/store/native_tasks_test.go
index 00785c2..d82576e 100644
--- a/internal/store/native_tasks_test.go
+++ b/internal/store/native_tasks_test.go
@@ -42,7 +42,13 @@ func newNativeTasksTestStore(t *testing.T) *Store {
 			recurrence_weekdays TEXT DEFAULT '',
 			recurrence_series_id TEXT DEFAULT '',
 			next_occurrence_override TEXT DEFAULT '',
-			estimated_minutes INTEGER DEFAULT 0
+			estimated_minutes INTEGER DEFAULT 0,
+			chain_id TEXT DEFAULT '',
+			chain_position INTEGER DEFAULT 0,
+			chain_unlocked BOOLEAN DEFAULT 0,
+			bucket_id TEXT DEFAULT '',
+			bucket_state TEXT DEFAULT '',
+			bucket_last_active_at DATETIME
 		)
 	`); err != nil {
 		t.Fatal(err)
@@ -68,6 +74,28 @@ func newNativeTasksTestStore(t *testing.T) *Store {
 	`); err != nil {
 		t.Fatal(err)
 	}
+	if _, err := db.Exec(`
+		CREATE TABLE task_chains (
+			id TEXT PRIMARY KEY,
+			project_id TEXT NOT NULL,
+			status TEXT NOT NULL DEFAULT 'active',
+			created_at DATETIME DEFAULT CURRENT_TIMESTAMP
+		)
+	`); err != nil {
+		t.Fatal(err)
+	}
+	if _, err := db.Exec(`
+		CREATE TABLE maintenance_buckets (
+			id TEXT PRIMARY KEY,
+			name TEXT NOT NULL,
+			cycle_days INTEGER NOT NULL,
+			pick_n INTEGER NOT NULL,
+			last_cycle_at DATETIME,
+			created_at DATETIME DEFAULT CURRENT_TIMESTAMP
+		)
+	`); err != nil {
+		t.Fatal(err)
+	}
 	if _, err := db.Exec(`INSERT INTO native_tasks (id, content) VALUES ('real-1', 'Real task')`); err != nil {
 		t.Fatal(err)
 	}