feat: memory staleness caveats

[kokevidaurre]

Context

Claude Code appends a staleness caveat when injecting memories older than 1 day:

"This memory is N days old. Memories are point-in-time observations, not live state — claims about code behavior or file:line citations may be outdated. Verify against current code before asserting as fact."

This prevents agents from acting on stale information — a root cause of duplicate issues and contradicting fixes in our system.

From Claude Code Source

memoryAge.ts:

memoryAgeDays(mtimeMs) = floor((Date.now() - mtimeMs) / 86_400_000)
memoryFreshnessText(mtimeMs) = age > 1 day ? staleness caveat : ''

The caveat is injected as a <system-reminder> before the memory content.

Current State

Our state.md files have no age signal. An agent reads state.md written 3 days ago and treats it as current truth. This causes:

• Acting on resolved blockers
• Re-filing closed issues
• Contradicting decisions made in intervening runs

Proposed Changes

In run-context.ts, when loading state.md or topic files:

1. Check file mtime
2. If > 24 hours old, prepend caveat:

   ⚠️ This memory is {N} days old. Verify against current state before acting on it.
   

3. If > 7 days old, stronger caveat:

   ⚠️ This memory is {N} days old and likely outdated. Check git log and current issues before relying on it.
   

Files to change

• src/lib/run-context.ts — add staleness check when reading memory files (~3 lines)

Expected impact

Minimal code change, significant quality improvement. Agents will verify stale state instead of blindly acting on it.