docs(session-log): state.db is canonical; ~/.hermes/sessions/ is legacy

CONTRIBUTING.md

@@ -210,7 +210,7 @@ hermes-agent/
 | `~/.hermes/skills/` | All active skills (bundled + hub-installed + agent-created) |
 | `~/.hermes/memories/` | Persistent memory (MEMORY.md, USER.md) |
 | `~/.hermes/state.db` | SQLite session database |
-| `~/.hermes/sessions/` | JSON session logs |
+| `~/.hermes/sessions/` | Legacy session artifacts (no longer written; state.db is canonical). Holds the gateway routing index (`sessions.json`) and request-dump breadcrumbs. |
 | `~/.hermes/cron/` | Scheduled job data |
 | `~/.hermes/whatsapp/session/` | WhatsApp bridge credentials |
 
@@ -239,7 +239,7 @@ User message → AIAgent._run_agent_loop()
 
 - **Self-registering tools**: Each tool file calls `registry.register()` at import time. `model_tools.py` triggers discovery by importing all tool modules.
 - **Toolset grouping**: Tools are grouped into toolsets (`web`, `terminal`, `file`, `browser`, etc.) that can be enabled/disabled per platform.
-- **Session persistence**: All conversations are stored in SQLite (`hermes_state.py`) with full-text search and unique session titles. JSON logs go to `~/.hermes/sessions/`.
+- **Session persistence**: All conversations are stored in SQLite (`hermes_state.py`) with full-text search and unique session titles. Per-session JSON snapshots in `~/.hermes/sessions/` were superseded by the SQLite store and are no longer written.
 - **Ephemeral injection**: System prompts and prefill messages are injected at API call time, never persisted to the database or logs.
 - **Provider abstraction**: The agent works with any OpenAI-compatible API. Provider resolution happens at init time (Nous Portal OAuth, OpenRouter API key, or custom endpoint).
 - **Provider routing**: When using OpenRouter, `provider_routing` in config.yaml controls provider selection (sort by throughput/latency/price, allow/ignore specific providers, data retention policies). These are injected as `extra_body.provider` in API requests.