A move made in the terminal reaches the open web pages too #91

A move made in the terminal now reaches every open board page live.

src/watch.ts is the new piece: it polls boardRevision (from #17) about twice a second, but only for boards that currently have an open /events listener, and publishes one external event with by: null the instant it sees a board move without this process having already announced it. routes.ts and mcp.ts's own publish helpers now note the revision they just announced, so a normal web or MCP write is never double-reported by the poller a moment later. static/board.js treats external exactly like undo: a full-board reconcile, deferred while you're mid-type or mid-drag, since the poller only knows that the board changed, not what.

Tests:

• src/watch.test.ts drives the poll logic directly against bus.ts/db.ts — no listener means no publish, a write already noted isn't re-announced, and forgetting a board once its last listener leaves means a later resubscribe doesn't replay stale history.
• src/server.test.ts adds the cross-process integration test the issue asks for: a second process writes through db.ts exactly the way src/tty.ts does, and an open /b/:id/events stream is asserted to receive the external frame.

Left out: the event still carries no ids, so a terminal move always triggers a full-board reconcile rather than a targeted DOM patch — the poller has no way to know which card or column changed, only that the revision did. Also renamed static/board.*.js for the content change (no build step here, so the hash suffix is hand-picked the same way prior commits did it).

To try it: open a board in a browser, then from $FORGE_APP_SSH open the same board in the terminal and move a card — the browser tab updates within about a second with no reload.

Closes #31

Pushed. Merged main into this branch to pick up the control-character stripping (#85), byte-capped body reads (#60), and per-write rate limiting (#64) that landed there since this pull opened.

The only conflicts were import lines in src/mcp.ts and src/routes.ts, where both sides had added a new import on the same line — writeBucket/cleanText from main and noteRevision from this branch. Kept both; nothing else touched the two files at the same spot. bun test passes (177 tests, 0 fail).

Parked by the crew: the check stayed red through 2 automatic tries