initial: identity resolution plugin

- Plugin manifest (plugin.yaml) with pre_gateway_dispatch + on_session_start hooks
- /identity slash command for config management
- Honcho injector patch docs (6 lines in plugins/memory/honcho/__init__.py)
- Config file at /opt/data/identity-config.json for persistence
- Kanban task body convention: context_peer: <name>
- Sample config with thierry/catherine mappings

Architecture: user-installed plugin (hooks + CLI) + 6-line Honcho bundled plugin change

plugin.yaml

@@ -0,0 +1,11 @@
+name: identity
+version: 1.0.0
+description: >
+  Identity resolution plugin for Hermes. Maps platform-specific user IDs
+  (Discord snowflake, Telegram UID, terminal) and kanban boards to stable
+  Honcho peer names. Config file at /opt/data/identity-config.json for
+  persistence across container rebuilds.
+author: "@gortium"
+hooks:
+  - pre_gateway_dispatch
+  - on_session_start