feat(orchestrator)!: S0 English everywhere, Sécurité, NATO hashes, ICAO digits

Requirement 001 phase 6, S0:

- Speech: the security class shows as "Sécurité" and is spoken as in
  maritime radio, "say-cure-ee-tay" three times. A hex run of 7 or more
  characters with a letter and a digit (commit, session, message ids) is
  spelled in the NATO alphabet; every other digit is spoken on its own
  in ICAO pronunciation (42305: four two tree zero fife). The spelling
  runs inside clip() before the length cut, so a phrase still fits
  SPEECH_LIMIT; the displayed text keeps its digits and hashes.
- English: every orchestrator label, tooltip, message, error, script
  output, document and test string is English (Regeln -> Firewall,
  Hierarchie -> Hierarchy, Steuerung -> Controls, Ausführen -> Run, ...);
  the page declares lang="en" and formats dates as en-GB. Task filter
  ids are English. German stays only in the skill trigger phrases that
  quote the operator, and as identifiers: the view keys (view=) and the
  leitstand id.
- tests/test_english.py scans every tracked text file for umlauts and
  German words, with an allowlist of the quoted trigger phrases.

BREAKING CHANGE: the Stream search tokens art: and seit: are now kind:
and since:; an old art: or seit: token counts as a plain word.

Evidence: make test 657 OK, ruff and markdownlint clean
(/tmp/s0-make-test-1.log); e2e 17 OK, none skipped (/tmp/s0-e2e-1.log);
MEDUSA 86 files, 24 findings on reworded strings accepted after an
independent skeptic (21 path:line, 0 rejected, no behaviour change in
signing, approving, rules, denying, offices, events), rescan 0 open.

🎯 Fix: 93 %
💥 Break: 4 %
💸 Cost: 100 %
⏱️ Time: –
🛡️ Security: 100 %
🏆 Score: 89
🚦 Gate: ✅ 90/5, cost and time <= 100, security 100 %

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

tests/test_hub_tasks.py

@@ -179,10 +179,10 @@ class TestHubTasks(HubCase):
         forged = {**self.signed([change(PRIO)], self.pin()), "assertion": {}}
         status, _, body = self.post_json("/api/tasks", {"items": [change(PRIO)], "proof": forged}, self.guard(self.host))
         self.assertEqual(status, 400, body)
-        self.assertIn("nicht signiert", body.decode() if isinstance(body, bytes) else body)
+        self.assertIn("not signed", body.decode() if isinstance(body, bytes) else body)
         snapshot = self.snapshot()
         self.assertEqual([job for job in snapshot["jobs"] if job["kind"] == "task"], [])
-        self.assertNotIn("Aufgabe signiert geändert", json.dumps(snapshot, ensure_ascii=False))
+        self.assertNotIn("Task change signed", json.dumps(snapshot, ensure_ascii=False))
 
     def test_a_task_the_hub_cannot_sign_whole_is_not_editable(self):
         long_slug = "work/" + "x" * 600