docs(arch): memory-vs-entities, promotion-rules, conflict-model

Three planning docs that answer the architectural questions the
engineering query catalog raised. Together with the catalog they
form roughly half of the pre-implementation planning sprint.

docs/architecture/memory-vs-entities.md
---------------------------------------
Resolves the central question blocking every other engineering
layer doc: is a Decision a memory or an entity?

Key decisions:
- memories stay the canonical home for identity, preference, and
  episodic facts
- entities become the canonical home for project, knowledge, and
  adaptation facts once the engineering layer V1 ships
- no concept lives in both layers at full fidelity; one canonical
  home per concept
- a "graduation" flow lets active memories upgrade into entities
  (memory stays as a frozen historical pointer, never deleted)
- one shared candidate review queue across both layers
- context builder budget gains a 15% slot for engineering entities,
  slotted between identity/preference memories and retrieved chunks
- the Phase 9 memory extractor's structural cues (decision heading,
  constraint heading, requirement heading) are explicitly an
  intentional temporary overlap, cleanly migrated via graduation
  when the entity extractor ships

docs/architecture/promotion-rules.md
------------------------------------
Defines the full Layer 0 → Layer 2 pipeline:

- four layers: L0 raw source, L1 memory candidate/active, L2 entity
  candidate/active, L3 trusted project state
- three extraction triggers: on interaction capture (existing),
  on ingestion wave (new, batched per wave), on explicit request
- per-rule prior confidence tuned at write time by structural
  signal (echoes the retriever's high/low signal hints) and
  freshness bonus
- batch cap of 50 candidates per pass to protect the reviewer
- full provenance requirements: every candidate carries rule id,
  source_chunk_id, source_interaction_id, and extractor_version
- reversibility matrix for every promotion step
- explicit no-auto-promotion-in-V1 stance with the schema designed
  so auto-promotion policies can be added later without migration
- the hard invariant: nothing ever moves into L3 automatically
- ingestion-wave extraction produces a report artifact under
  data/extraction-reports/<wave-id>/

docs/architecture/conflict-model.md
-----------------------------------
Defines how AtoCore handles contradictory facts without violating
the "bad memory is worse than no memory" rule.

- conflict = two or more active rows claiming the same slot with
  incompatible values
- per-type "slot key" tuples for both memory and entity types
- cross-layer conflict detection respects the trust hierarchy:
  trusted project state > active entities > active memories
- new conflicts and conflict_members tables (schema proposal)
- detection at two latencies: synchronous at write time,
  asynchronous nightly sweep
- "flag, never block" rule: writes always succeed, conflicts are
  surfaced via /conflicts, /health open_conflicts_count, per-row
  response bodies, and the Human Mirror's disputed marker
- resolution is always human: promote-winner + supersede-others,
  or dismiss-as-not-a-real-conflict, both with audit trail
- explicitly out of scope for V1: cross-project conflicts,
  temporal-overlap conflicts, tolerance-aware numeric comparisons

Also updates:
- master-plan-status.md: Phase 9 moved from "started" to "baseline
  complete" now that Commits A, B, C are all landed
- master-plan-status.md: adds a "Engineering Layer Planning Sprint"
  section listing the doc wave so far and the remaining docs
  (tool-handoff-boundaries, human-mirror-rules,
  representation-authority, engineering-v1-acceptance)
- current-state.md: Phase 9 moved from "not started" to "baseline
  complete" with the A/B/C annotation

This is pure doc work. No code changes, no schema changes, no
behavior changes. Per the working rule in master-plan-status.md:
the architecture docs shape decisions, they do not force premature
schema work.

docs/current-state.md

@@ -19,12 +19,12 @@ now includes a first curated ingestion batch for the active projects.
   - Phase 3
   - Phase 5
   - Phase 7
+  - Phase 9 (Commits A/B/C: capture, reinforcement, extractor + review queue)
 - partial
   - Phase 4
   - Phase 8
 - not started
   - Phase 6
-  - Phase 9
   - Phase 10
   - Phase 11
   - Phase 12