Close v1 swarm: fresh-participant smoke test, join retries, README fleet note.

Retry announce/manifest while Tor circuits warm on NODE and startup bootstrap.
Add verify_swarm_fresh_participant.py for empty-volume GHCR smoke tests.

Co-authored-by: Cursor <cursoragent@cursor.com>

backend/tests/mesh/test_swarm_join_retries.py

@@ -0,0 +1,25 @@
+from services.mesh import mesh_swarm_runtime as swarm
+
+
+def test_join_swarm_with_retries_succeeds_on_second_attempt(monkeypatch):
+    calls = {"n": 0}
+
+    def fake_announce(*, force=True):
+        calls["n"] += 1
+        if calls["n"] < 2:
+            return {"ok": False, "results": [{"ok": False, "status_code": 503}]}
+        return {"ok": True, "results": [{"ok": True, "status_code": 200}]}
+
+    def fake_manifest(*, force=True, now=None):
+        if calls["n"] < 2:
+            return {"ok": False, "detail": "manifest fetch failed"}
+        return {"ok": True, "peer_count": 3, "merged_peer_count": 3}
+
+    monkeypatch.setattr(swarm, "announce_local_peer_to_seeds", fake_announce)
+    monkeypatch.setattr(swarm, "refresh_swarm_manifest_from_seeds", fake_manifest)
+    monkeypatch.setattr(swarm.time, "sleep", lambda _s: None)
+
+    joined = swarm.join_swarm_with_retries(attempts=3, delay_s=1.0)
+
+    assert joined["ok"] is True
+    assert joined["attempts"] == 2