bench: every board-runnable tool ported to the bench page

The remaining bench diagnostics run from forgetest's #bench tab. The
tools that also run from a LAN host share scripts/bench/gfbench.py:
GF_HOST names a remote machine (host mode, sysfs through ssh, Grbl and
forgectrl over the LAN); unset, the tool runs on the board itself
(local mode, sysfs directly, everything on 127.0.0.1), which is how the
page runs them - with GF_HOST=127.0.0.1, the panel token in GF_TOKEN
and their data files under <data>/bench/ (FORGETEST_BENCH_DATA). The
helper also reads a machine setting from forgectrl, or from the settings
file on the board while forgectrl is stopped.

Ported: pwm_sweep / pwm_hold (scope = a takeover; the latch relocked,
the write refused if FIRE or LASER_ON reads active), pwm_stream_test
(PASS/FAIL exit), flow_characterize, flow_recheck_char,
flow_warm_validate and flow_matrix (takeovers: forgectrl owns the
thermal hardware, so the page's takeover replaces the tools' own
controller stop/restart, whose command line predated the supervisor;
results and logs in the bench data directory), flow_sustained,
fan_test, temp_calibrate (dry; watch bounded in seconds; the threshold
and the coolant conversion from the shared code), flow_escalate_drill
(cool_confirm_max_s shortened through forgectrl's settings for the
drill and restored; the setting's minimum is the default budget), and
live_fire_drills (<drill> [S] [F], all six drills, host from GF_HOST,
token from the board). flow_matrix joins the registry. What stays
unported cannot run against the machine at all: the two null-sink CI
harnesses and the .puls decoder.

Runner: a scope tool runs inside the takeover wrapper; the bench
environment above is passed to every tool. Tests: test_bench_registry
(registry <-> scripts/bench consistency, every ported tool builds its
command line, every script compiles, gfbench host/local modes) and the
server test (scope tool takeover, the environment reaching the tool).
Local mode smoke-run on the bench (temp_calibrate watch, setting, token)
from /tmp, removed after.

No catalog consequence: bench tools are not image components (dev-only
forgetest); the acceptance catalog is unchanged.

scripts/bench/pwm_stream_test.py

@@ -12,8 +12,12 @@ Safety posture:
 - laser_latch re-asserted locked; lid closed; HV watchdog untouched.
 - Position counters compared before/after - must be identical.
 - streaming stays 0: end-of-data is a normal completion.
+
+Runs with the controller and forgectrl stopped (the bench page's
+takeover). Exit status 0 when the counters did not move, the run ended
+in an idle state and no FIRE/emission was read back; 1 otherwise.
 """
-import fcntl, mmap, os, struct, time
+import fcntl, mmap, os, struct, sys, time
 
 TICK_HZ = 10000
 PWM2_BASE = 0x02084000
@@ -88,15 +92,18 @@ try:
     dt = time.time() - t0
     print('done: state=%s after %.1f s' % (state, dt))
     pos_after = rd_pos()
-    print('post: pos before=%s after=%s  MOVED=%s'
-          % (pos_before, pos_after, pos_before[:3] != pos_after[:3]))
+    moved = pos_before[:3] != pos_after[:3]
+    print('post: pos before=%s after=%s  MOVED=%s' % (pos_before, pos_after, moved))
+    en, on, sampled = rd('cnc/laser_enable'), rd('cnc/laser_on'), rd('cnc/laser_on_sampled')
     print('post: laser_enable=%s laser_on=%s laser_on_sampled=%s faults=%s underruns=%s'
-          % (rd('cnc/laser_enable'), rd('cnc/laser_on'),
-             rd('cnc/laser_on_sampled'), rd('cnc/faults'), rd('cnc/underruns')))
+          % (en, on, sampled, rd('cnc/faults'), rd('cnc/underruns')))
     print('post: PWMSAR=%d  (duty after end-of-data)' % pwmsar())
+    ok = (not moved) and state == 'idle' and en == '0' and on == '0' and sampled == '0'
 finally:
     fcntl.flock(fd, fcntl.LOCK_UN)
     os.close(fd)
 
 wr('cnc/disable', 1)
 print('safe state restored: state=%s' % rd('cnc/state'))
+print('RESULT %s' % ('PASS' if ok else 'FAIL'))
+sys.exit(0 if ok else 1)