fix: exclude tool messages from FTS indexes to prevent trigram bloat

[503496348-ops]

Problem

FTS triggers index ALL messages including role='tool' (JSON execution output). Tool messages are 72% of indexed content but rarely useful for search. Trigram tokenizer amplifies to 3-5x source size.

Impact: cto-bot state.db 650MB (425MB FTS) -> 310MB after fix.

Fix

• WHEN new.role != 'tool' on INSERT/UPDATE triggers
• Index only content (not tool_name + tool_calls)

Storage Impact

Metric	Before	After
Indexed	123.6 MB	14.6 MB (-88%)
FTS	717 MB	~60 MB (-92%)

[teknium1]

Thanks for targeting a real FTS storage cost. This needs rework before the proposed behavior can be evaluated safely.

Problems

• Existing databases would retain the old triggers: FTS setup uses CREATE ... IF NOT EXISTS (hermes_state.py:1157-1171), and the existing v11 migration explicitly drops/recreates FTS objects because those statements do not replace existing triggers (hermes_state.py:1499-1550). This PR adds no equivalent migration or backfill.
• Replacing the indexed expression with content alone removes current tool-metadata search behavior. tests/test_hermes_state.py:4627-4663 requires tool_name and serialized tool_calls to be FTS-searchable, while tests/tools/test_session_search.py:290-296 covers an explicit role_filter='tool' search.

Suggested changes

• Preserve the current assistant tool-call metadata contract, or propose and test a replacement search surface.
• If tool-result exclusion is intended, add a versioned migration that rebuilds both FTS indexes and tests populated upgrades plus fresh databases.

Automated hermes-sweeper review.

[teknium1]

Closing with credit — tool-row exclusion from the FTS indexes shipped on main in PR #65798 (schema v23). You were the earliest submitter on this idea (May 31) and the diagnosis was exactly right: tool output dominates indexed bytes and the trigram tokenizer amplifies it.

The merged design differs in one respect: tool rows are excluded from the trigram index only, while the standard FTS index keeps them — tool-output search (role_filter=['tool']) is a supported session_search path (#16751), so dropping tool rows from both indexes would have broken it. Combined with the external-content layout, the result on a real 25 GB production DB was −60%.

Thanks @503496348-ops for flagging this early with real numbers (650 MB → 310 MB).