/sync-gbrain Step 4 writes false code-search guidance into CLAUDE.md on markdown-only brains

[erlendm]

Summary

On a markdown-only brain (no registered code source), /sync-gbrain Step 4 writes the ## GBrain Search Guidance block into the user's CLAUDE.md claiming working .gbrain-source pins and gbrain code-def/code-refs/code-callers symbol search. None of that resolves against anything — the code source never registered. The agent is then instructed to use tools that return nothing, and the block silently overwrites any hand-corrected version on every run.

Environment

• gstack v1.55.0.0
• gbrain 0.42.8.0, engine pglite (local-stdio MCP), macOS
• Brain: single default markdown source at the repo path; ~/.gstack/ artifacts; no code source

Repro

1. Have a brain where the repo path is registered as the markdown default source (a standard /setup-gbrain outcome).

2. Run /sync-gbrain. The orchestrator's code stage fails:

   ERR  code  source registration failed: gbrain sources add
   gstack-code-… failed: path "/…/repo" overlaps with existing source
   "default" at "/…/repo". Overlapping sources are not allowed.
   

3. Step 4's capability check (CAPABILITY_OK) still passes — it only tests a markdown put/search/delete round-trip, which works.

4. Because CAPABILITY_OK=1, Step 4 writes the verbatim template asserting code-symbol search. The block now tells the agent to use code-def etc., which have a 0-page corpus.

Root cause

Step 4 gates the code-search template on the markdown capability check, not on whether the code source actually registered. Step 3 already computes the code source page_count, but only uses it to prompt for a --full reindex — it doesn't feed the Step 4 branch. So page_count=0 still yields code-search guidance.

Compounding: a code source can't even register when it overlaps the default markdown source at the same path (the error above), so on these brains code search is structurally impossible — yet the guidance claims it works.

Suggested fix

Gate the code-search portion of the Step 4 template on the code source's real page_count (already available from Step 3), not on CAPABILITY_OK:

• code source page_count > 0 → write the full template (code + memory).
• code source absent / page_count == 0 → write a markdown-only variant (semantic/keyword search + ~/.gstack/ memory; point code-symbol questions at Grep).

Optionally, when the code stage fails with the overlap error, surface it as a real warning instead of letting Step 4 paper over it.

Secondary: stale template content

The current template recommends gbrain autopilot --install for "ongoing auto-sync," and the "Safety" note warns about a running gbrain autopilot. The autopilot command is gone in gbrain 0.42.x (replaced by sync --watch / sync --install-cron). On pglite (single-writer) a background sync daemon also can't coexist with an always-on MCP gbrain serve — that combination crash-loops. The template should drop the autopilot --install guidance.