Bug

The official AGENTS.md template (reference/templates/AGENTS.md) uses ## Every Session and ## Safety as section headers. However, post-compaction-context.ts extracts sections named ## Session Startup and ## Red Lines.

This means any workspace using the official template loses startup context after compaction — extractSections() returns null because the expected headers don't match.

Evidence

Code (from bundled dist):

const sections = extractSections(
  await fs.promises.readFile(agentsPath, "utf-8"),
  ["Session Startup", "Red Lines"]
);

Template (reference/templates/AGENTS.md):

## Every Session    ← code expects "Session Startup"
## Safety           ← code expects "Red Lines"

The BARE_SESSION_RESET_PROMPT (used by /new and /reset) also references "Session Startup".

CHANGELOG #22338 confirms the feature expects "Session Startup".

Expected fix

Update the template to use ## Session Startup and ## Red Lines, or update the code to accept both naming conventions.