Development Plan: every agent is its own container image

Each agent ships as its own image, since that's how it runs on the agent
host. nisse-review's image becomes M7.6, ahead of the agent host; its
deployment moves to M7.7. nisse-ops' image comes with its first slice.
Also fixes two stale references to M7.6.

Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01J5Utyfzw7gF7UhjRDEtjTk

nisse-dev/src/nisse_dev/loop/agent.py

@@ -3056,7 +3056,7 @@ class LoopAgent:
         """Block a build VM (D3): every project on it waits until it is
         recovered. Said once at top level, and in each waiting item's thread.
         The recovery is the operator's for now, or the VM's coming back;
-        nisse-ops' later (M7.6)."""
+        nisse-ops' later (M8.5)."""
         if host in self._store.vm_blocks():
             return  # already said
         self._store.block_vm(