Phase 4: memory_update, typed relations and hybrid RRF search (MCP-06, MCP-07, STORE-05, SEARCH-04, SEARCH-05) #5

Tracking issue for milestone v1.1 (product v0.1.0), Phase 4 — Memory Update, Relations & Hybrid Search.

Scope

• MCP-06 memory_update (MCP + PATCH /api/memories/{id}): patch content/tags/scope/TTL; content edits re-mirror FTS and re-embed in the same writer transaction.
• MCP-07 memory_link / memory_unlink with flat typed relations, cascade on forget and TTL sweep, and 1-hop expand_links on search and list.
• STORE-05 migration 0003 with hygiene: frozen 0001/0002 SQL, pre-migration backup, friendly error when a newer DB meets an older binary.
• SEARCH-04 / SEARCH-05 decay-aware hybrid RRF search; degrades to keyword exactly as v1.0 when Ollama is unreachable.

Gap closure after first verification (13/15)

• Forgiving keyword leg: raw FTS5 first, one sanitized retry; punctuation like sqlite-vec / auth: tokens no longer 500s; search errors never leak SQLite text.
• Sweep backfill never overwrites an edited or forgotten row (CR-03).
• relates_to is one symmetric relation; memory_update refuses unknown fields; REST path/query errors get the JSON body; race-safe pre-migration backup.
• WR-04: memory_list with expand_links and no limit is rejected (400 / invalid_params).

Re-verification: passed 28/28.