/flow lists approved pulls waiting on the merge queue, stale crew pulls to fold back, and work a crew fork never proposed #11455

Intent: nothing sits unseen in the lane: three quiet places work waits, each with its one action.

Done:

• [ ] approvedWait (src/flow/approved_wait.ts): per repository, how many approved pulls wait and how long the oldest has
• [ ] staleFold (src/flow/stale_fold.ts): crew pulls with no push in 7 days, oldest first, each with the note that folds it back into its issue; it only proposes, a person closes
• [ ] unproposed alarm (src/flow/alarm_unproposed.ts): a crew fork's branch 6 h old or more that heads no pull, shown once with a link to the branch
• [ ] one test per section on the page's HTML; empty sections draw nothing (no empty card)

Done means reachable: the module leaves scripts/unreached-allow.json in the same pull (test/unreached.test.ts goes red on an entry that is no longer unreached), the page is reachable from /flow in two taps, and a test fails without the wiring. Read the module and src/web/pages/flow.ts first; if main already calls it, say so in the pull with the commit. Add the section as its own small builder file and mount it with one line, so pulls on the other flow modules do not collide.

Files: the three modules, a new src/web/pages/flow-waiting.ts, src/web/pages/flow.ts (one mount line), scripts/unreached-allow.json, docs/features/flow-waiting.md, tests. Risks: reading branches per fork is a git call; use the branches page's helpers and never pass a branch name to a shell. Suggested brief: mason.