feat(#956): add MemPalace memory capability (ADR-857 feature plug-in) (#1201)

* feat(#956): add MemPalace memory capability (ADR-857 feature plug-in)

Adds an opt-in, default-resilient ADR-857 feature capability that wires
MemPalace (local-first memory: MCP server + CLI) into the GSD loop:
deliberate recall before discuss/plan and verbatim + temporal-KG capture
at phase boundaries. Three memory modes (augment default; kg_backend and
replace forward-declared). Master gate mempalace.enabled (default off);
every hook onError:skip, zero gates; absent/disabled MemPalace => loop
unchanged. Transport is rendered-markdown only — MemPalace runs
out-of-process, no third-party code in gsd-core (ADR-857 §7).

Capability: capabilities/mempalace/ (manifest + 2 fragments), skills
commands/gsd/mempalace-{recall,capture}.md, agent
agents/gsd-mempalace-curator.md. Registration: ns-context router,
utility cluster, KNOWN_SKILLS, help full.md, model-catalog, copilot
install list, size baselines; regenerated capability-registry +
inventory manifest. ship:post wired into ship.md (wire-on-demand).

HELD on #1196: this capability also declares hooks at discuss:pre and
discuss:post, which are structurally un-wireable until the host-loop
conformance model covers the discuss phase (discuss-phase.md is not in
HOST_LOOP_FILES). The phase6-capstone-conformance gate therefore fails
on exactly those two orphaned points by design — see #1196. Once #1196
lands, rebase onto next and the gate goes green with no further change.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

* docs(#956): backfill changeset PR number (#1201)

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

---------

Co-authored-by: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

docs/INVENTORY.md

@@ -51,6 +51,7 @@ Full roster at `agents/gsd-*.md`. The "Primary doc" column flags whether [`docs/
 | gsd-intel-updater | Writes structured intel files (`.planning/intel/*.json`) used as a queryable codebase knowledge base. | `/gsd-map-codebase --query` | advanced stub |
 | gsd-doc-classifier | Classifies a single planning document as ADR, PRD, SPEC, DOC, or UNKNOWN; spawned in parallel to process the doc corpus. | `/gsd-ingest-docs` | advanced stub |
 | gsd-doc-synthesizer | Synthesizes classified planning docs into a single consolidated context with precedence rules, cycle detection, and three-bucket conflicts report. | `/gsd-ingest-docs` | advanced stub |
+| gsd-mempalace-curator | Ship-time MemPalace curation — diary entry, cross-project tunnel proposals, wing-scoped sync pruning, and extract-learnings → KG mirroring with provenance. | MemPalace capability at `ship:post` | advanced stub |
 
 **Coverage note.** `docs/AGENTS.md` gives full role cards for the primary agents plus concise stubs for the advanced agents. The Agent Tool Permissions Summary in that file covers only the primary agents; the advanced agents' tool lists are captured in their per-agent frontmatter in `agents/gsd-*.md`.
 
@@ -138,6 +139,8 @@ These six routers are descriptor-only entries that the model picks first; the bo
 | `/gsd-map-codebase` | Analyze codebase with parallel mapper agents; use `--fast` for lightweight scan or `--query` for intel queries. | [commands/gsd/map-codebase.md](../commands/gsd/map-codebase.md) |
 | `/gsd-graphify` | Build, query, and inspect the project knowledge graph in `.planning/graphs/`. | [commands/gsd/graphify.md](../commands/gsd/graphify.md) |
 | `/gsd-extract-learnings` | Extract decisions, lessons, patterns, and surprises from completed phase artifacts. | [commands/gsd/extract-learnings.md](../commands/gsd/extract-learnings.md) |
+| `/gsd-mempalace-recall` | Recall prior decisions, patterns, and surprises from MemPalace into MEMORY-RECALL.md before planning. | [commands/gsd/mempalace-recall.md](../commands/gsd/mempalace-recall.md) |
+| `/gsd-mempalace-capture` | File a phase artifact (CONTEXT/PLAN/SUMMARY) verbatim into MemPalace and mirror decision facts into its temporal KG. | [commands/gsd/mempalace-capture.md](../commands/gsd/mempalace-capture.md) |
 
 ### Review, Debug & Recovery