Update memory system skill and plugin

plugins/memory/memory_system/README.md

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+# Hermes Memory System Plugin
+
+This Hermes memory provider talks to the Memory System API instead of calling OpenViking or EverOS directly.
+
+It stores completed Hermes turns through:
+
+- `POST /memory-system/messages`
+- `POST /memory-system/sessions/{session_id}/commit` on session end
+- `POST /memory-system/search` for recall
+- `GET /memory-system/users/{user_id}/profile` for user profile reads
+
+## Configure
+
+Put these values in the Hermes profile env file, usually `~/.hermes/.env`:
+
+```dotenv
+MEMORY_SYSTEM_ENDPOINT=http://127.0.0.1:1934
+MEMORY_SYSTEM_USER_ID=default
+MEMORY_SYSTEM_API_KEY=
+MEMORY_SYSTEM_SEARCH_USE_LLM=false
+MEMORY_SYSTEM_COMMIT_EVERY_TURNS=5
+MEMORY_SYSTEM_COMMIT_INTERVAL_SECONDS=300
+MEMORY_SYSTEM_TIMEOUT_SECONDS=180
+```
+
+You can also keep a separate file and point to it with `MEMORY_SYSTEM_ENV_FILE`.
+Real environment variables still override file values.
+
+Then select this provider in Hermes memory config:
+
+```yaml
+memory:
+  provider: memory_system
+```
+
+## Tools
+
+- `memory_system_search`: search OpenViking and EverOS via Memory System API.
+- `memory_system_profile`: read the EverOS profile memory for the active user.
+- `memory_system_remember`: explicitly write an important memory and commit the session.
+
+The plugin commits after 5 new turns or 300 seconds by default, whichever comes first.
+Set either value to `0` to disable that trigger. Session end still commits any new turns that were not already committed.
+
+`MEMORY_SYSTEM_TIMEOUT_SECONDS` should be long enough for commit/search calls that wait on EverOS LLM extraction or rerank services. The default is 180 seconds.
+
+If commit returns `partial_success`, the plugin logs the response and does not mark the pending turns as committed, so a later periodic commit or session-end commit can retry EverOS flush.
+
+Search responses from current Memory System API versions do not include raw `vector` fields. The API strips those large embedding arrays before returning merged results or backend debug payloads.
+
+The plugin is intentionally thin. User identity, session identity, backend writes, OpenViking commit, and EverOS flush stay owned by Memory System API.