feat: import agents_and_robots platform as unibots (Matrix-out, unibus transport)

Reemplaza el scaffold del echobot por la plataforma completa de bots traida
desde ~/DataProyects/Github/agents_and_robots tras la operacion Matrix-out:
los bots ya no hablan por Matrix sino por el bus unibus (modelo todo-rooms +
E2E via shell/transportunibus sobre github.com/enmanuel/unibus/pkg/client).

- go.mod: replace de unibus -> ../unibus y de fn-registry -> ../../../.. (paths
  relativos reajustados a la nueva ubicacion dentro de fn_registry).
- app.md: bump a 0.2.0, descripcion + arquitectura + comandos + gotchas reales.
- modulo Go conservado como github.com/enmanuel/agents (sin reescribir imports).

agents_and_robots queda archivado como museo de la era Matrix.

config/matrix.yaml

@@ -0,0 +1,13 @@
+# Global Matrix configuration
+# Agent-specific overrides go in agents/<name>/config.yaml
+
+homeserver: "${MATRIX_HOMESERVER}"
+server_name: "${MATRIX_SERVER_NAME}"
+
+# Shared rooms — reference these IDs in per-agent configs
+rooms:
+  alerts: "${MATRIX_ROOM_ALERTS}"
+  logs: "${MATRIX_ROOM_LOGS}"
+  admin: "${MATRIX_ROOM_ADMIN}"
+  audit: "${MATRIX_ROOM_AUDIT}"
+  agents_internal: "${MATRIX_ROOM_AGENTS_INTERNAL}"

config/servers.yaml

@@ -0,0 +1,28 @@
+# Global SSH server inventory
+# Referenced by target name in agent configs
+
+defaults:
+  user: deploy
+  port: 22
+  key_file_env: SSH_PRIVATE_KEY_PATH
+  timeout: 10s
+  keepalive_interval: 15s
+
+targets:
+  production:
+    hosts:
+      - "${PROD_HOST_1}"
+      - "${PROD_HOST_2}"
+    user: deploy
+    jump_host: "${BASTION_HOST}"
+
+  staging:
+    hosts:
+      - "${STAGING_HOST}"
+    user: deploy
+
+  monitoring:
+    hosts:
+      - "${MONITORING_HOST}"
+    user: monitor
+    key_file_env: SSH_MONITOR_KEY_PATH