feat: per-site SHIFT path with video search, fix agent token injection, accept cpu_temp

- deploy_agent.sh: agent v3.3-shift — use dashboard-configured SHIFT path for
  file fetch/search (SR/SHIFT sites have no TAKELEAP folder), date fast-path;
  fix installer discarding the injected agent token (sentinel was being
  rewritten by the server's placeholder replace, agents ended up tokenless)
- central_api_prototype.py: replace only the token assignment when serving the
  installer; add cpu_temp to TelemetryPayload (agents already send it, it was
  silently dropped); new endpoints set-shift-path, request-search,
  search-results; heartbeat response now carries shift_path + pending search
- commands.json: restore last_reboot/dummy, add update_diag diagnostic
- CLAUDE.md: document deployment layout, procedures, and gotchas

commands.json

@@ -324,6 +324,19 @@
       "/opt/seekright-agent/client_agent_prototype.py",
       "--list-takeleap-sub-files",
       "UPLOAD_FOLDER"
+    ],
+    "last_reboot": [
+      "last",
+      "reboot"
+    ],
+    "dummy": [
+      "last",
+      "reboot"
+    ],
+    "update_diag": [
+      "bash",
+      "-c",
+      "echo HOST:$(hostname); echo USER:$(id -un); echo MACHINE_ID:$(cat /etc/machine-id 2>/dev/null); echo AGENT_PROCS:; pgrep -af client_agent_prototype 2>/dev/null; echo APT_PROCS:; ps aux | grep -E \"apt-get|apt |dpkg|unattended\" | grep -v grep; echo UPDATE_UNITS:; systemctl list-units \"run-r*\" --no-legend --all 2>&1 | head -5"
     ]
   }
-}
+}