release: v1.2.3 — mempalace-mcp self-heal (toolkit e12b624)

Patch release. Headline: mempalace-mcp self-heals instead of latching
available=false permanently after a slow virtiofs cold-open. Base image
rebuilds via the mempalace-toolkit ref advancing to e12b624 (folded into
the base-decide hash). No pi/mempalace version change — pi npm latest is
still 0.80.2 (= v1.2.2). Also releases the queued yq (mikefarah Go yq) and
mempalace-skill temporal-grounding changes.

CHANGELOG.md

@@ -13,8 +13,40 @@ Pre-v1.0.0 tags followed the pi npm version (`v{pi_version}[letter]`).
 
 ## Unreleased
 
+---
+
+## v1.2.3 — 2026-06-27
+
+Patch release. Headline: **mempalace-mcp now self-heals** instead of latching
+`available=false` permanently after a slow cold-open. Also folds in the `yq`
+and mempalace-skill changes that were sitting unreleased. **No pi/mempalace
+version change** — pi npm `latest` is still `0.80.2` (= v1.2.2) and the
+mempalace pin stays `3.5.0`; the base image rebuilds purely because the
+`mempalace-toolkit` ref advances to pick up the self-heal extension.
+
 ### Fixed
 
+- **mempalace-mcp self-heal — no more permanent `available=false` latch.**
+  The `mempalace.ts` pi extension (from `mempalace-toolkit`, bumped to
+  [`e12b624`](https://gitea.jordbo.se/joakimp/mempalace-toolkit/commit/e12b624))
+  previously tripped its per-request timeout on a slow virtiofs cold-open of
+  the palace, killed the child, and set `available=false` **forever** (no
+  respawn) — a pi restart was the only recovery.
+  - **Bounded respawn with capped exponential backoff** via `ensureAlive()`
+    (`MEMPALACE_MCP_MAX_RESPAWNS=2`, `MEMPALACE_MCP_RESPAWN_BACKOFF_MS=1000`;
+    set max to `0` to disable). Both `execute()` and initial startup route
+    through it. The respawn budget **resets on any successful JSON-RPC
+    response** (`onStdout`), so a healthy session can't slowly exhaust it.
+  - **Scoped init timeout** raised `120000 → 300000` ms (`MEMPALACE_MCP_INIT_TIMEOUT_MS`),
+    affecting **init only** — the per-call timeout stays `60000`
+    (`MEMPALACE_MCP_TIMEOUT_MS`) — so a genuine cold HNSW deserialize isn't
+    killed mid-open.
+  - **Concurrency hardening:** a generation counter prevents a late-exiting
+    killed process from clobbering a fresh respawn, and an explicit `healthy`
+    flag replaces the racy `proc != null` check.
+  - Note: the build-time `smoke-test.sh` verifies the extension is present and
+    deployed but does **not** exercise respawn behaviour — first live
+    validation is on a running container.
 - **`yq` is now mikefarah's Go yq, not Debian's Python `yq`.** The base image
   previously apt-installed `yq`, which on Debian/Ubuntu is the unrelated
   kislyuk/`yq` (a jq wrapper, v3.x) — incompatible with the mikefarah v4 syntax