Never undo settings applied on the page: sync from NA Ingest, rebase stale drafts, guard the installer

- config.json is NA Ingest's live settings: the READY hours (Tue 14-22, Wed 9-19, Sun 5-14) and the
  auto-fix hours (Tue 14-22, Wed 9-21, Sun 6:30-14) set on the settings page.
- Settings page: a draft carries what its page started from. A tab that loaded the settings before
  they changed (an Apply elsewhere, a program update) now has only its own edits put on top of the
  live settings; before, it saved its whole older copy and Apply quietly undid the newer values
  (it took ready.prop_host out twice today).
- install.sh refuses (exit 4) to replace live settings that came from an Apply (their fingerprint is
  a history entry's sha_after) unless --replace-config; --keep-config still updates code only.
- Tests pin their own auto-fix and READY hours, so the campus can change its own; the exit-timeout
  test expects 310 s (the Tascam outlet power-cycle).

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

tests/test_settings.py

@@ -291,6 +291,27 @@ class TestServer(unittest.TestCase):
         self.assertEqual(len(v["changes"]), 1); self.assertTrue(v["changes"][0]["text"].startswith("computer Lighting PC › notes"))
         self.put("/api/draft", {}, method="DELETE")
 
+    def test_a_page_that_loaded_before_a_change_never_undoes_it(self):
+        """2026-10-15: a tab loaded the settings, a program update then added ready.prop_host, the tab
+        changed one window and saved its whole (older) copy - Apply took prop_host out again. Now the
+        page says what it started from and only its own change goes on top of the live settings."""
+        import hashlib
+        before = self.site.load(); base_sha = self.site.cfg_sha
+        newer = json.loads(json.dumps(before)); newer["debounce_seconds"] = (before.get("debounce_seconds") or 3) + 2
+        sp.write_json(self.site.config_path, newer)                                          # changed under the page
+        self.site.load()
+        page = json.loads(json.dumps(before)); page["flap"] = dict(before.get("flap") or {}, count=7)   # the page's own edit
+        st, r = self.put("/api/draft", {"config": page, "base": base_sha, "base_config": before}, who="christian")
+        self.assertTrue(r["rebased"])
+        d = self.site.draft.read()["config"]
+        self.assertEqual(d["flap"]["count"], 7)                                              # the page's change
+        self.assertEqual(d["debounce_seconds"], newer["debounce_seconds"])                    # the newer value kept
+        st, r = self.put("/api/draft", {"config": d, "base": self.site.cfg_sha, "base_config": d}, who="christian")
+        self.assertFalse(r["rebased"])                                                       # up to date: nothing to do
+        self.put("/api/draft", {}, method="DELETE")
+        sp.write_json(self.site.config_path, before)
+        self.site.load()
+
     def test_probe_is_refused_while_a_fix_runs(self):
         json.dump({"fix-x": {"key": "hd2"}}, open(os.path.join(self.data, "fixes-running.json"), "w"))
         try: