feat: add app status tracking to the backend (#17163)

This does ~95% of the backend work required to integrate the AI work.

Most left to integrate from the tasks branch is just frontend, which
will be a lot smaller I believe.

The real difference between this branch and that one is the abstraction
-- this now attaches statuses to apps, and returns the latest status
reported as part of a workspace.

This change enables us to have a similar UX to in the tasks branch, but
for agents other than Claude Code as well. Any app can report status
now.

coderd/database/queries/workspaceapps.sql

@@ -42,3 +42,18 @@ SET
 	health = $2
 WHERE
 	id = $1;
+
+-- name: InsertWorkspaceAppStatus :one
+INSERT INTO workspace_app_statuses (id, created_at, workspace_id, agent_id, app_id, state, message, needs_user_attention, uri, icon)
+VALUES ($1, $2, $3, $4, $5, $6, $7, $8, $9, $10)
+RETURNING *;
+
+-- name: GetWorkspaceAppStatusesByAppIDs :many
+SELECT * FROM workspace_app_statuses WHERE app_id = ANY(@ids :: uuid [ ]);
+
+-- name: GetLatestWorkspaceAppStatusesByWorkspaceIDs :many
+SELECT DISTINCT ON (workspace_id)
+  *
+FROM workspace_app_statuses 
+WHERE workspace_id = ANY(@ids :: uuid[])
+ORDER BY workspace_id, created_at DESC;