feat(ui): add maintenance page for task management

* Implement maintenance page with task and log display
* Add backfill and metadata retry functionality
* Integrate grid component for project display in thoughts page
* Update types for maintenance tasks and logs
* Enhance sidebar and shell for new maintenance navigation

migrations/_old/005_create_match_thoughts.sql

@@ -0,0 +1,31 @@
+create or replace function match_thoughts(
+  query_embedding vector(1536),
+  match_threshold float default 0.7,
+  match_count int default 10,
+  filter jsonb default '{}'::jsonb
+)
+returns table (
+  id uuid,
+  content text,
+  metadata jsonb,
+  similarity float,
+  created_at timestamptz
+)
+language plpgsql
+as $$
+begin
+  return query
+  select
+    t.guid,
+    t.content,
+    t.metadata,
+    1 - (t.embedding <=> query_embedding) as similarity,
+    t.created_at
+  from thoughts t
+  where 1 - (t.embedding <=> query_embedding) > match_threshold
+    and t.archived_at is null
+    and (filter = '{}'::jsonb or t.metadata @> filter)
+  order by t.embedding <=> query_embedding
+  limit match_count;
+end;
+$$;