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.

forgetest/tests/test_server.py

@@ -62,7 +62,9 @@ class ServerTests(unittest.TestCase):
         cls.tooldir = os.path.join(cls.tmp, "bench")
         os.makedirs(cls.tooldir)
         with open(os.path.join(cls.tooldir, "echo_tool.py"), "w") as f:
-            f.write("import sys, time\nprint('args', sys.argv[1:])\nsys.stdout.flush()\n"
+            f.write("import os, sys, time\nprint('args', sys.argv[1:])\n"
+                    "print('env', os.environ.get('GF_HOST'), os.environ.get('FORGETEST_BENCH_DATA'))\n"
+                    "sys.stdout.flush()\n"
                     "if 'slow' in sys.argv: time.sleep(30)\nsys.exit(0 if 'fail' not in sys.argv else 3)\n")
         tools = [{"id": "echo", "title": "Echo", "script": "echo_tool.py", "safety": "dry", "where": "board",
                   "ported": True, "desc": "echo",
@@ -73,6 +75,8 @@ class ServerTests(unittest.TestCase):
                  {"id": "hot", "title": "H", "script": "echo_tool.py", "safety": "live", "where": "board",
                   "ported": True, "desc": "", "args": []},
                  {"id": "tk", "title": "T", "script": "echo_tool.py", "safety": "takeover", "where": "board",
+                  "ported": True, "desc": "", "args": []},
+                 {"id": "sc", "title": "S", "script": "echo_tool.py", "safety": "scope", "where": "board",
                   "ported": True, "desc": "", "args": []}]
         cls.bench = bench_mod.Bench(tools, tool_dir=cls.tooldir,
                                     index_path=os.path.join(cls.tmp, "bench.jsonl"))
@@ -261,7 +265,7 @@ class ServerTests(unittest.TestCase):
         st, d = self.call("GET", "/bench")
         self.assertEqual(st, 200)
         ids = [t["id"] for t in d["tools"]]
-        self.assertEqual(ids, ["echo", "unported", "hot", "tk"])
+        self.assertEqual(ids, ["echo", "unported", "hot", "tk", "sc"])
         st, d = self.call("POST", "/bench/start", {"tool": "unported"})
         self.assertEqual(st, 409)
         st, d = self.call("POST", "/bench/start", {"tool": "hot"})
@@ -274,6 +278,9 @@ class ServerTests(unittest.TestCase):
         self.assertEqual(state["last_run"]["kind"], "bench")
         self.assertEqual(state["last_run"]["finished"]["result"], "OK")
         self.assertTrue(any("['yo', '5']" in l for l in state["last_run"]["log"]))
+        # the bench environment: the machine is local, data under <data>/bench
+        self.assertTrue(any(" env 127.0.0.1 " in l and l.endswith("bench")
+                            for l in state["last_run"]["log"]), state["last_run"]["log"])
         st, d = self.call("GET", "/bench")
         self.assertEqual(d["tools"][0]["last"]["result"]["result"], "OK")
         # a failing tool and an aborted one
@@ -295,6 +302,13 @@ class ServerTests(unittest.TestCase):
         self.assertIn("takeover: forgectrl start", log)
         self.assertIn("baseline: forgectrl unreachable for 10 s", log)
         self.assertFalse(os.path.exists(os.environ["FORGETEST_MARKER"]))
+        # a scope tool is a takeover too
+        st, d = self.call("POST", "/bench/start", {"tool": "sc"})
+        self.assertEqual(st, 200, d)
+        state = self.wait_idle(timeout=40)
+        log = "\n".join(state["last_run"]["log"])
+        self.assertIn("takeover: pulse device free", log)
+        self.assertIn("takeover: forgectrl start", log)
         # bench runs never touched the acceptance log
         recs = self.log.read()
         self.assertFalse(any(r.get("t") == "result" and r.get("test") == "echo" for r in recs))