feat: add long-term memory systems with fused retrieval and memory explorer

Phase 5 (ADR-0003). pkg/concepts fixes the epistemic vocabulary
(observation, fact, memory, claim, hypothesis, belief, prediction,
assumption, inference, opinion), memory kinds and relation names.

internal/memory stores episodic, semantic, procedural and
autobiographical memories in one mind-scoped table with trust-derived
credibility, importance, salience and decaying activation. Retrieval
fuses full-text rank (any-term by default), optional pgvector similarity,
recency, activation, importance and credibility, and returns the
component scores so every recall can be explained. Decay lowers
activation and never deletes; retraction and supersession keep rows for
provenance. Relationships are constrained to one mind at insert time.
Embeddings live in a conditional pgvector table keyed by model so vector
spaces are never mixed; without an embedder the system degrades to text
and graph retrieval.

Attention gates encoding: the attend handler turns admitted observations
into episodic memories (operator changes become autobiographical ones)
with memory_created events; the retrieve process proposes recalled
memories as candidates and admitted recalls are reinforced with
memory_retrieved events carrying their scoring components.

Memory explorer UI (search with component breakdown, timeline, filters,
operator knowledge entry), memory detail with provenance, relationships,
citing events and an inaccurate-memory correction; API; noemactl memory
commands; decay and embed-missing background jobs.

PLAN.md

@@ -80,13 +80,16 @@ An administrator can: start Noema → log in → create a mind → configure per
 - ☑ `noemactl workspace show|cycle|pause|resume|reset`
 - ☑ Tests: scoring determinism and bounds, ranking order, admission/refresh/capacity/decay/prune, provenance chain across a cycle, restart continuity, no self-triggered cycles, loop suppression, pause/reset/cancellation
 
-### Phase 5 – Episodic and semantic memory
-- ☐ `migrations/0005_memory`: memories (kinds, tsvector), memory_relationships, memory_embeddings (conditional pgvector)
-- ☐ `internal/memory`: typed stores, retrieval fusion with recorded component scores, reinforcement, decay job, isolation by mind
-- ☐ `internal/embeddings`: interface, pgvector adapter, none-adapter
-- ☐ Processes: memory retrieval, novelty detection
-- ☐ UI: memory explorer (search, timeline, filters, evidence, relationships)
-- ☐ Tests: retrieval scoring, decay, isolation, fallback without pgvector
+### Phase 5 – Episodic and semantic memory ☑
+- ☑ `pkg/concepts`: epistemic kinds, memory kinds, relation vocabulary
+- ☑ `migrations/0005_memory`: memories (kinds, epistemic status, trust/credibility, importance, activation, tsvector), memory_relationships, conditional pgvector memory_embeddings
+- ☑ `internal/embeddings`: interface, None fallback, pgvector formatting
+- ☑ `internal/memory`: mind-scoped store, fused retrieval with recorded components (text any-term/strict, vector, recency, activation, importance, credibility), reinforcement, decay without deletion, relationships, statuses, stats, embed-missing job
+- ☑ Processes and handlers: `retrieve` proposes recalls as candidates; `attend` handler encodes attended events as episodic/autobiographical memories; `retrieve` handler reinforces and records `memory_retrieved`
+- ☑ API: list/search, create (operator knowledge), detail with relationships and citing events, retract, relate, stats
+- ☑ UI: memory explorer (search with component scores, timeline, filters, add knowledge), memory detail (provenance, strength, relationships, correction)
+- ☑ `noemactl memory search|list|inspect|add`; decay and embedding background jobs; docs/memory.md
+- ☑ Tests: lifecycle, fused retrieval, cross-mind isolation (retrieve, get, relate), reinforcement, decay, retraction, stats
 
 ### Phase 6 – Beliefs, evidence, confidence, contradictions
 - ☐ `migrations/0006_beliefs`: beliefs, belief_versions (append-only), belief_evidence, corrections