feat(tess): add configurable pi interaction service

packages/mosaic/framework/fleet/README.md

@@ -15,6 +15,21 @@ default tmux server.
 
 - `examples/minimal.yaml` starts one local canary slot.
 - `examples/local-canary.yaml` starts a small generic dogfood fleet.
+- `examples/operator-interaction.yaml` is an example Pi operator-interaction
+  service; replace its example agent name before provisioning.
+
+## Operator interaction service
+
+`services/operator-interaction.yaml` pins the Pi runtime, GPT-5.6 Sol model,
+high reasoning, and the `operator-interaction` tool policy. The agent identity
+is provisioning data: choose a roster name, generate its per-agent environment
+file, then start the matching generic systemd instance. The service fails before
+launch if the configured identity does not match the instance or any pinned
+policy field drifts.
+
+The installed `tools/fleet/print-interaction-effective-policy.sh` prints only
+the resolved name, runtime, model, reasoning, and tool policy. It never reads
+or prints credential variables.
 
 Initialize a roster: