feat: implement session management and terminal handling with UI updates and backend support

uvm/install.py

@@ -2,6 +2,8 @@
 
 from __future__ import annotations
 
+import hashlib
+import json
 import os
 import shlex
 import shutil
@@ -397,12 +399,17 @@ class Installer:
         machine_id.symlink_to("../../../etc/machine-id")
         for key in (root / "etc/ssh").glob("ssh_host_*_key*"):
             key.unlink()
-        for guest_path, contents in guest_agent_files().items():
+        agent_payloads = guest_agent_files()
+        for guest_path, contents in agent_payloads.items():
             path = root / guest_path.lstrip("/")
             path.parent.mkdir(parents=True, exist_ok=True)
             path.parent.chmod(0o755)
             path.write_bytes(contents)
             path.chmod(0o644)
+        manifest = root / "etc/uvm-agent-files.json"
+        manifest.write_text(json.dumps({name: hashlib.sha256(data).hexdigest() for name, data in agent_payloads.items()},
+                                       sort_keys=True) + "\n", encoding="utf-8")
+        manifest.chmod(0o600)
         self._runner.run(("systemctl", "--root", root, "enable", "ssh.service", "systemd-networkd.service",
                           "uvm-agent.service"), capture=True)
         self._runner.run(("systemctl", "--root", root, "set-default", "multi-user.target"), capture=True)