step-6: add memory models and migration (models.py, alembic)

- User.encryption_key: per-user Fernet key generated on registration
- MemoryCore: encrypted key/value preferences
- MemoryAssociative: encrypted semantic memory + pgvector(1536) embedding
- MemoryEpisodic: encrypted session summaries
- MemoryProactive: encrypted behavioral patterns with confidence score
- Migration 004: enables pgvector extension, creates all 4 tables + ivfflat index
- auth.py register: generates Fernet key for new users
- 8 unit tests pass (SQLite in-memory, JSON embedding fallback)

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

app/api/routes/auth.py

@@ -13,6 +13,7 @@ import uuid
 from datetime import datetime, timedelta, timezone
 
 import bcrypt
+from cryptography.fernet import Fernet
 from fastapi import APIRouter, Depends, HTTPException, status
 from jose import jwt
 from pydantic import BaseModel
@@ -94,6 +95,7 @@ async def register(
         email=body.email,
         password_hash=_hash_password(body.password),
         tier="free",
+        encryption_key=Fernet.generate_key().decode(),
     )
     db.add(user)
     await db.flush()  # get user.id without committing

app/models.py

@@ -14,6 +14,10 @@ Table inventory:
   plugin_installations — per-user install records
   plugin_reviews      — admin review decisions
   revenue_events      — Stripe Connect 70/30 split ledger
+  memory_core         — per-user persistent key/value preferences (encrypted)
+  memory_associative  — per-user semantic memory with embeddings (encrypted)
+  memory_episodic     — per-user session summaries (encrypted)
+  memory_proactive    — per-user behavioral patterns (encrypted)
 """
 
 from __future__ import annotations
@@ -74,6 +78,9 @@ class User(Base):
     password_hash: Mapped[str] = mapped_column(String(255), nullable=False)
     tier: Mapped[str] = mapped_column(TierEnum, nullable=False, default="free")
     stripe_customer_id: Mapped[str | None] = mapped_column(String(255), nullable=True)
+    # Per-user Fernet key (base64-urlsafe, 44 chars). Generated on registration.
+    # Used to encrypt/decrypt all memory rows for this user.
+    encryption_key: Mapped[str | None] = mapped_column(String(64), nullable=True)
     created_at: Mapped[datetime] = mapped_column(
         DateTime(timezone=True), nullable=False, server_default=func.now()
     )
@@ -375,3 +382,93 @@ class AgentRunLog(Base):
         foreign_keys="AgentRunLog.agent_id",
         overlaps="run_logs,local_agent",
     )
+
+
+# ── Memory models ─────────────────────────────────────────────────────────────
+
+
+class MemoryCore(Base):
+    """Per-user persistent key/value preferences, encrypted at rest.
+
+    Examples: preferred_language, timezone, work_style.
+    Decrypted in-memory only using User.encryption_key.
+    """
+
+    __tablename__ = "memory_core"
+
+    id: Mapped[str] = mapped_column(Uuid(as_uuid=False), primary_key=True, default=_uuid)
+    user_id: Mapped[str] = mapped_column(
+        Uuid(as_uuid=False), ForeignKey("users.id", ondelete="CASCADE"),
+        nullable=False, index=True,
+    )
+    key: Mapped[str] = mapped_column(String(255), nullable=False)
+    value_encrypted: Mapped[str] = mapped_column(Text, nullable=False)
+    updated_at: Mapped[datetime] = mapped_column(
+        DateTime(timezone=True), nullable=False, server_default=func.now(), onupdate=func.now()
+    )
+
+
+class MemoryAssociative(Base):
+    """Per-user semantic memory: encrypted content + pgvector embedding for similarity search.
+
+    Production: ``embedding`` column is ``vector(1536)`` via pgvector.
+    Tests (SQLite): stored as JSON list.
+    """
+
+    __tablename__ = "memory_associative"
+
+    id: Mapped[str] = mapped_column(Uuid(as_uuid=False), primary_key=True, default=_uuid)
+    user_id: Mapped[str] = mapped_column(
+        Uuid(as_uuid=False), ForeignKey("users.id", ondelete="CASCADE"),
+        nullable=False, index=True,
+    )
+    content_encrypted: Mapped[str] = mapped_column(Text, nullable=False)
+    # JSON-encoded float list in SQLite tests; vector(1536) in Postgres via migration.
+    embedding: Mapped[list | None] = mapped_column(JSON, nullable=True)
+    entity_type: Mapped[str | None] = mapped_column(String(100), nullable=True)
+    entity_id: Mapped[str | None] = mapped_column(String(255), nullable=True)
+    updated_at: Mapped[datetime] = mapped_column(
+        DateTime(timezone=True), nullable=False, server_default=func.now(), onupdate=func.now()
+    )
+
+
+class MemoryEpisodic(Base):
+    """Per-user session summaries, encrypted at rest.
+
+    One row per session interaction; used to recall recent conversations.
+    """
+
+    __tablename__ = "memory_episodic"
+
+    id: Mapped[str] = mapped_column(Uuid(as_uuid=False), primary_key=True, default=_uuid)
+    user_id: Mapped[str] = mapped_column(
+        Uuid(as_uuid=False), ForeignKey("users.id", ondelete="CASCADE"),
+        nullable=False, index=True,
+    )
+    summary_encrypted: Mapped[str] = mapped_column(Text, nullable=False)
+    session_id: Mapped[str] = mapped_column(String(255), nullable=False, index=True)
+    created_at: Mapped[datetime] = mapped_column(
+        DateTime(timezone=True), nullable=False, server_default=func.now()
+    )
+
+
+class MemoryProactive(Base):
+    """Per-user inferred behavioral patterns, encrypted at rest.
+
+    Confidence in [0.0, 1.0]; only patterns above threshold are injected.
+    Source: 'inferred' (from episodes) or 'explicit' (user-stated).
+    """
+
+    __tablename__ = "memory_proactive"
+
+    id: Mapped[str] = mapped_column(Uuid(as_uuid=False), primary_key=True, default=_uuid)
+    user_id: Mapped[str] = mapped_column(
+        Uuid(as_uuid=False), ForeignKey("users.id", ondelete="CASCADE"),
+        nullable=False, index=True,
+    )
+    pattern_encrypted: Mapped[str] = mapped_column(Text, nullable=False)
+    confidence: Mapped[float] = mapped_column(Float, nullable=False, default=0.5)
+    source: Mapped[str] = mapped_column(String(50), nullable=False, default="inferred")
+    created_at: Mapped[datetime] = mapped_column(
+        DateTime(timezone=True), nullable=False, server_default=func.now()
+    )