docs(session_search): update all docs for the single-shape rewrite (#27840)

Companion PR to #27590. Sweeps remaining stale references to the
LLM-summary path that landed in main with #27590 but weren't fully
caught in the followup cleanup commit.

Real rewrites:
- user-guide/sessions.md: 'Session Search Tool' section rewritten to
  describe the three calling shapes (discovery / scroll / browse) with
  worked examples. Adds the 'Optional parameters' subsection covering
  sort and role_filter.
- user-guide/features/memory.md: 'Session Search' overview rewritten,
  comparison table updated (speed: ms instead of LLM summarization,
  added explicit free-cost row, link to sessions.md for details).

Stale-claim sweeps:
- user-guide/configuring-models.md: drop the 'Session Search' row from
  the aux-model override table (no aux model anymore), drop session
  search from the auxiliary-models list.
- user-guide/features/codex-app-server-runtime.md: drop session_search
  from the ChatGPT-subscription cost note, drop the session_search
  block from the per-task override config example.
- developer-guide/provider-runtime.md: drop 'session search
  summarization' from the auxiliary tasks list.
- developer-guide/agent-loop.md: drop session search from the
  auxiliary fallback chain list.
- user-guide/skills/.../autonomous-ai-agents-hermes-agent.md: drop
  session_search from the 'auxiliary models not working' debug step.

Untouched (still accurate as tool-name mentions, not behavioral claims):
- features/tools.md, features/honcho.md, features/acp.md
- cli.md, sessions.md (other sections)
- developer-guide/tools-runtime.md, agent-loop.md (line 157)
- acp-internals.md, adding-tools.md, prompt-assembly.md
- reference/toolsets-reference.md, reference/tools-reference.md

website/docs/user-guide/features/codex-app-server-runtime.md

@@ -242,7 +242,7 @@ default_permissions = ":read-only"
 
 ## Auxiliary tasks and ChatGPT subscription token cost
 
-When this runtime is on with the `openai-codex` provider, **auxiliary tasks (title generation, context compression, vision auto-detect, session search summarization, the background self-improvement review fork) also flow through your ChatGPT subscription by default**, because Hermes' auxiliary client uses the main provider/model when no per-task override is set.
+When this runtime is on with the `openai-codex` provider, **auxiliary tasks (title generation, context compression, vision auto-detect, the background self-improvement review fork) also flow through your ChatGPT subscription by default**, because Hermes' auxiliary client uses the main provider/model when no per-task override is set.
 
 This isn't specific to `codex_app_server` — it's true for the existing `codex_responses` path too — but it's more visible here because you're explicitly opting in for the subscription billing.
 
@@ -259,9 +259,6 @@ auxiliary:
   vision_detect:
     provider: openrouter
     model: google/gemini-3-flash-preview
-  session_search:
-    provider: openrouter
-    model: google/gemini-3-flash-preview
   goal_judge:
     provider: openrouter
     model: google/gemini-3-flash-preview

website/docs/user-guide/features/memory.md

@@ -177,19 +177,23 @@ Memory entries are scanned for injection and exfiltration patterns before being
 Beyond MEMORY.md and USER.md, the agent can search its past conversations using the `session_search` tool:
 
 - All CLI and messaging sessions are stored in SQLite (`~/.hermes/state.db`) with FTS5 full-text search
-- Search queries return relevant past conversations with Gemini Flash summarization
+- Search queries return actual messages from the DB — no LLM summarization, no truncation
 - The agent can find things it discussed weeks ago, even if they're not in its active memory
+- The agent can also scroll forward/backward inside any session it finds
 
 ```bash
 hermes sessions list    # Browse past sessions
 ```
 
+See [Session Search Tool](/docs/user-guide/sessions#session-search-tool) for the three calling shapes (discovery / scroll / browse) and the response format.
+
 ### session_search vs memory
 
 | Feature | Persistent Memory | Session Search |
 |---------|------------------|----------------|
 | **Capacity** | ~1,300 tokens total | Unlimited (all sessions) |
-| **Speed** | Instant (in system prompt) | Requires search + LLM summarization |
+| **Speed** | Instant (in system prompt) | ~20ms FTS5 query, ~1ms scroll |
+| **Cost** | Token cost in every prompt | Free — no LLM calls |
 | **Use case** | Key facts always available | Finding specific past conversations |
 | **Management** | Manually curated by agent | Automatic — all sessions stored |
 | **Token cost** | Fixed per session (~1,300 tokens) | On-demand (searched when needed) |