feat(supermemory): add multi-container, search_mode, identity template, and env var override (#5933)

Based on PR #5413 spec by MaheshtheDev (Mahesh Sanikommu).

Changes:
- Add search_mode config (hybrid/memories/documents) passed to SDK
- Add {identity} template support in container_tag for profile-scoped containers
- Add SUPERMEMORY_CONTAINER_TAG env var override (priority over config)
- Add multi-container mode: enable_custom_container_tags, custom_containers,
  custom_container_instructions in supermemory.json
- Dynamic tool schemas when multi-container enabled (optional container_tag param)
- Whitelist validation for custom container tags in tool calls
- Simplify get_config_schema() to only prompt for API key during setup
- Defer container_tag sanitization to initialize() (after template resolution)
- Add custom_id support to documents.add calls
- Update README with multi-container docs, search_mode, identity template,
  support links (Discord, email)
- Update memory-providers.md with new features and multi-container example
- Update memory-provider-plugin.md with minimal vs full schema guidance
- Add 12 new tests covering identity template, search_mode, multi-container,
  config schema, and env var override

plugins/memory/supermemory/README.md

@@ -17,7 +17,7 @@ Or manually:
 
 ```bash
 hermes config set memory.provider supermemory
-echo 'SUPERMEMORY_API_KEY=your-key-here' >> ~/.hermes/.env
+echo 'SUPERMEMORY_API_KEY=***' >> ~/.hermes/.env
 ```
 
 ## Config
@@ -26,15 +26,23 @@ Config file: `$HERMES_HOME/supermemory.json`
 
 | Key | Default | Description |
 |-----|---------|-------------|
-| `container_tag` | `hermes` | Container tag used for search and writes |
+| `container_tag` | `hermes` | Container tag used for search and writes. Supports `{identity}` template for profile-scoped tags (e.g. `hermes-{identity}` → `hermes-coder`). |
 | `auto_recall` | `true` | Inject relevant memory context before turns |
 | `auto_capture` | `true` | Store cleaned user-assistant turns after each response |
 | `max_recall_results` | `10` | Max recalled items to format into context |
 | `profile_frequency` | `50` | Include profile facts on first turn and every N turns |
 | `capture_mode` | `all` | Skip tiny or trivial turns by default |
+| `search_mode` | `hybrid` | Search mode: `hybrid` (profile + memories), `memories` (memories only), `documents` (documents only) |
 | `entity_context` | built-in default | Extraction guidance passed to Supermemory |
 | `api_timeout` | `5.0` | Timeout for SDK and ingest requests |
 
+### Environment Variables
+
+| Variable | Description |
+|----------|-------------|
+| `SUPERMEMORY_API_KEY` | API key (required) |
+| `SUPERMEMORY_CONTAINER_TAG` | Override container tag (takes priority over config file) |
+
 ## Tools
 
 | Tool | Description |
@@ -52,3 +60,40 @@ When enabled, Hermes can:
 - store cleaned conversation turns after each completed response
 - ingest the full session on session end for richer graph updates
 - expose explicit tools for search, store, forget, and profile access
+
+## Profile-Scoped Containers
+
+Use `{identity}` in the `container_tag` to scope memories per Hermes profile:
+
+```json
+{
+  "container_tag": "hermes-{identity}"
+}
+```
+
+For a profile named `coder`, this resolves to `hermes-coder`. The default profile resolves to `hermes-default`. Without `{identity}`, all profiles share the same container.
+
+## Multi-Container Mode
+
+For advanced setups (e.g. OpenClaw-style multi-workspace), you can enable custom container tags so the agent can read/write across multiple named containers:
+
+```json
+{
+  "container_tag": "hermes",
+  "enable_custom_container_tags": true,
+  "custom_containers": ["project-alpha", "project-beta", "shared-knowledge"],
+  "custom_container_instructions": "Use project-alpha for coding tasks, project-beta for research, and shared-knowledge for team-wide facts."
+}
+```
+
+When enabled:
+- `supermemory_search`, `supermemory_store`, `supermemory_forget`, and `supermemory_profile` accept an optional `container_tag` parameter
+- The tag must be in the whitelist: primary container + `custom_containers`
+- Automatic operations (turn sync, prefetch, memory write mirroring, session ingest) always use the **primary** container only
+- Custom container instructions are injected into the system prompt
+
+## Support
+
+- [Supermemory Discord](https://supermemory.link/discord)
+- [support@supermemory.com](mailto:support@supermemory.com)
+- [supermemory.ai](https://supermemory.ai)