Prove the controller's published state files

The lifecycle harness gains the state-files scenario: with GF_STATE_DIR
at the session workdir, grbl.settings carries the $$ view and follows
the derived floor through an M101 switch and its M2 revert, and
grbl.state follows the sender connection (a reconnect bumps the
generation), the armed window and the dose model, with ts_mono
advancing. The panel-serves catalog test asserts the /status grbl block
in GRBL mode with a live controller (fresh age, state, sender, laser,
modals) and GET /grbl/settings, and its covers name the publisher and
the serial layer; the glowforge_status.c covers entry selects nothing
until the grblHAL pin moves past the commit that adds the file. The
CAMPAIGN-LOG records the build and its proof; BRINGUP describes the
mechanism.

docs/BRINGUP.md

@@ -315,6 +315,20 @@ regardless of the sender's M8/M9; a SUSPECT/FAULT verdict inside an armed
 window takes the safe posture (feed hold + run airflow). SUSPECT auto-resumes
 on a clean re-check; FAULT leaves the hold and the gate for the operator.
 
+**The controller publishes its state for the daemon.** forgectrl can
+never open the Grbl socket (a connection displaces the sender), so the
+controller writes two files under `/run/forgefirm`, atomically, on
+edges: `grbl.settings` (the `$$` view, rewritten on every setting
+change, the M101 switch included) and `grbl.state` (JSON: machine state
+and alarm, the sender session with peer and generation, the laser's
+armed window and dose model with its floor, the exact `[GC:...]` modal
+report, overrides, driver version, `ts_mono` for age; on change plus a
+5 s heartbeat). forgectrl echoes the state file in `GET /status` as the
+`grbl` block only while it supervises a live GRBL controller, serves
+the settings file at `GET /grbl/settings`, and the panel's GRBL card
+renders it. Position stays out: it changes per segment and is served
+from the kernel counters. Contract: `forgectrl/docs/SERVICES.md`.
+
 **Emission evidence.** `cnc/laser_on_sampled` (surfaced as `/status`
 `laser.emission_samples`) is the reliable live-emission witness; emission
 sensed with no armed window relocks the latch and stops motion. `pic/hv_current`