fix: keep embedded session controls visible and handle empty memory

Cap the embedded shell at its portal container height so steering and stop controls remain accessible. Skip vector retrieval for an empty authoritative Memory archive and compute SQL-rule embeddings lazily.

Validated with 54 Memory tests, 90 frontend tests, five browser scenarios, frontend and Docker builds, and a read-only comparison against the real empty Memory archive.

PROJECT_STATE.md

@@ -12,6 +12,18 @@ Authentik, internal catalog/embedding services, and the PSD workspace repository
 `docs/operations/server-upgrade-gitea-workspace-v2.md`. Treat its operator gates and rollback
 requirements as mandatory; do not replace the running server stack in place.
 
+## Session composer and empty Memory fix prepared — 2026-09-14
+
+The embedded shell now caps its height at the portal mount height, keeping steering
+and Stop & save visible. Empty authoritative Memory archives return zero results
+without requiring embedding/BM25; SQL-rule embedding is lazy and shared. The live
+empty PSD archive reproduces 503 with the current image and succeeds with the
+candidate. 54 Memory tests, 90 frontend tests, five browser scenarios and both image
+builds passed. Candidate core/frontend tags are `49333a2d-session-memory-fix`;
+production recreation awaits the release-window confirmation required by the server
+handoff. See `docs/reports/2026-09-14-session-layout-memory-fix.md` for evidence,
+prepared rollback and resolved deployment commands.
+
 ## Full/embedded shell and bilingual interface
 
 Full/embedded shell, EN/IT UI, immutable session interaction language, dark theme,