feat(host-agent): release_agent.sh — Binaries als Gitea-Assets, nicht im Tree

release_agent.sh <version> (wie die App-release.sh): setzt Version
(host_agent.py AGENT_VERSION + Android versionName/Code), baut Linux-Binary +
Android-APK per Docker, taggt agent-v<version> (eigener Namespace, keine
Kollision mit App-Tags v<version>), legt Gitea-Release an und laedt Assets hoch.
mac/win optional falls in dist/ vorgebaut. Agent meldet AGENT_VERSION jetzt in
host_hello + info. README-Release-Sektion aktualisiert.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

host-agent/host_agent.py

@@ -155,6 +155,9 @@ OUT_MAX_CHARS_HARD = int(os.environ.get("OUT_MAX_CHARS_HARD", "200000") or "2000
 # Datei-Transfer-Limit (Base64 durchs RVS).
 FILE_MAX_BYTES = int(os.environ.get("FILE_MAX_BYTES", str(10 * 1024 * 1024)) or str(10 * 1024 * 1024))
 
+# Version (wird von release_agent.sh beim Release gesetzt).
+AGENT_VERSION = "0.2.0"
+
 HEARTBEAT_SEC = 25
 CAPS = ["exec", "read", "write", "info", "screenshot"]
 
@@ -291,6 +294,7 @@ def _do_write(params: dict) -> dict:
 def _do_info(params: dict) -> dict:
     info = {
         "host": HOST_NAME, "hostname": socket.gethostname(),
+        "agent_version": AGENT_VERSION,
         "os": platform.platform(), "kernel": platform.release(),
         "arch": platform.machine(), "python": platform.python_version(),
         "user": os.environ.get("USER") or os.environ.get("USERNAME") or "",
@@ -414,7 +418,7 @@ class HostAgent:
                         HOST_ID, HOST_NAME, ",".join(CAPS), CONTROL_ENABLED)
         await self._send({"type": "host_hello", "payload": {
             "hostId": HOST_ID, "name": HOST_NAME, "os": platform.platform(),
-            "caps": CAPS, "control": CONTROL_ENABLED,
+            "version": AGENT_VERSION, "caps": CAPS, "control": CONTROL_ENABLED,
         }, "timestamp": int(time.time() * 1000)})
 
     async def _heartbeat(self) -> None: