skill(mempalace): teach temporal grounding (recreate != new day)

Baked mempalace SKILL.md now instructs agents to establish current date/time
and compute the delta against the actual diary/drawer timestamp before using
relative terms (yesterday/last week), and explicitly that a container recreate
or fresh session is NOT a day boundary (pi-devbox restarts several times a day).
Phase 1 wake-up section + anti-pattern bullet. CHANGELOG Unreleased.

CHANGELOG.md

@@ -25,6 +25,18 @@ Pre-v1.0.0 tags followed the pi npm version (`v{pi_version}[letter]`).
   asserts `yq --version` reports `mikefarah` **and** major **v4**, so both a
   regression to the Python package and a surprise future yq v5 fail CI.
 
+### Changed
+
+- **Baked `mempalace` skill now teaches temporal grounding.** Added a
+  *Temporal grounding* rule to the image-baked
+  `skills/mempalace/SKILL.md` (Phase 1 wake-up + a matching anti-pattern):
+  before using relative time terms ("yesterday", "last week"), establish the
+  current date/time and compute the delta against the actual diary/drawer
+  timestamp. Explicitly calls out that a **container recreate or fresh session
+  is not a day boundary** — pi-devbox restarts several times a day, so two
+  entries minutes apart can straddle a recreate. Fixes agents mislabelling
+  same-day sessions as "yesterday".
+
 ---
 
 ## v1.2.2 — 2026-06-24