Add AI Council architecture: Tier 2/3/Graph implementation + Integration Plan

Architecture (Agent 1):
- hermes_memory/tier2/{schema,facts,entities,relations,timeline}.py
- hermes_memory/tier3/{backend,chroma_backend,embedder}.py
- hermes_memory/graph/nx_store.py
- hermes_memory/api/memory_api.py (unified API)
- hermes_memory/cron/{consolidate,embed_queue,graph_refresh,prune}.py
- hermes_memory/config.py + pyproject.toml

Integration Plan (Agent 3):
- INTEGRATION_PLAN.md: Memory Provider Plugin strategy
- Hermes Core needs minimal changes
- sync_turn() + prefetch() hooks
- Skills integration via nextlevel_search/remember

Auto-Extraction (Agent 2):
- ARCHITECTURE.md: Full extraction pipeline docs
- Chunking, Pre-Filter, LLM Prompts, Classification
- Entity-Linking, Temporal Reasoning, Deduplication

All files: Python syntax checked, ECC standards applied.

hermes_memory/tier2/__init__.py

@@ -0,0 +1,20 @@
+"""Tier 2 — Structured Knowledge (SQLite)."""
+
+from hermes_memory.tier2.facts import Fact, FactStore
+from hermes_memory.tier2.entities import Entity, EntityStore
+from hermes_memory.tier2.relations import Relation, RelationStore
+from hermes_memory.tier2.timeline import TimelineEvent, TimelineStore
+from hermes_memory.tier2.schema import init_schema, migrate
+
+__all__ = [
+    "Fact",
+    "FactStore",
+    "Entity",
+    "EntityStore",
+    "Relation",
+    "RelationStore",
+    "TimelineEvent",
+    "TimelineStore",
+    "init_schema",
+    "migrate",
+]