feat(nordagpt): add memory tables and ORM models

- Migration 092: ai_user_memory (per-user facts with expiry)
- Migration 093: ai_conversation_summary (auto-generated summaries)
- SQLAlchemy models: AIUserMemory, AIConversationSummary

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

database.py

@@ -5951,6 +5951,44 @@ class MessagePin(Base):
         return f'<MessagePin msg={self.message_id} conv={self.conversation_id}>'
 
 
+class AIUserMemory(Base):
+    __tablename__ = 'ai_user_memory'
+
+    id = Column(Integer, primary_key=True)
+    user_id = Column(Integer, ForeignKey('users.id', ondelete='CASCADE'), nullable=False)
+    fact = Column(Text, nullable=False)
+    category = Column(String(50), default='general')
+    source_conversation_id = Column(Integer, ForeignKey('ai_chat_conversations.id', ondelete='SET NULL'), nullable=True)
+    confidence = Column(Float, default=1.0)
+    created_at = Column(DateTime, default=datetime.utcnow)
+    expires_at = Column(DateTime)
+    is_active = Column(Boolean, default=True)
+
+    user = relationship('User')
+    source_conversation = relationship('AIChatConversation')
+
+    def __repr__(self):
+        return f'<AIUserMemory id={self.id} user={self.user_id} fact="{self.fact[:30]}">'
+
+
+class AIConversationSummary(Base):
+    __tablename__ = 'ai_conversation_summary'
+
+    id = Column(Integer, primary_key=True)
+    conversation_id = Column(Integer, ForeignKey('ai_chat_conversations.id', ondelete='CASCADE'), nullable=False, unique=True)
+    user_id = Column(Integer, ForeignKey('users.id', ondelete='CASCADE'), nullable=False)
+    summary = Column(Text, nullable=False)
+    key_topics = Column(JSON, default=list)
+    created_at = Column(DateTime, default=datetime.utcnow)
+    updated_at = Column(DateTime, default=datetime.utcnow)
+
+    user = relationship('User')
+    conversation = relationship('AIChatConversation')
+
+    def __repr__(self):
+        return f'<AIConversationSummary conv={self.conversation_id}>'
+
+
 # ============================================================
 # DATABASE INITIALIZATION
 # ============================================================

database/migrations/092_ai_user_memory.sql

@@ -0,0 +1,20 @@
+-- 092_ai_user_memory.sql
+-- Persistent memory for NordaGPT — per-user facts extracted from conversations
+
+CREATE TABLE IF NOT EXISTS ai_user_memory (
+    id SERIAL PRIMARY KEY,
+    user_id INTEGER NOT NULL REFERENCES users(id) ON DELETE CASCADE,
+    fact TEXT NOT NULL,
+    category VARCHAR(50) DEFAULT 'general',
+    source_conversation_id INTEGER REFERENCES ai_chat_conversations(id) ON DELETE SET NULL,
+    confidence FLOAT DEFAULT 1.0,
+    created_at TIMESTAMP DEFAULT NOW(),
+    expires_at TIMESTAMP DEFAULT (NOW() + INTERVAL '12 months'),
+    is_active BOOLEAN DEFAULT TRUE
+);
+
+CREATE INDEX idx_ai_user_memory_user_active ON ai_user_memory(user_id, is_active, confidence DESC);
+CREATE INDEX idx_ai_user_memory_expires ON ai_user_memory(expires_at) WHERE is_active = TRUE;
+
+GRANT ALL ON TABLE ai_user_memory TO nordabiz_app;
+GRANT USAGE, SELECT ON SEQUENCE ai_user_memory_id_seq TO nordabiz_app;

database/migrations/093_ai_conversation_summary.sql

@@ -0,0 +1,17 @@
+-- 093_ai_conversation_summary.sql
+-- Auto-generated summaries of AI conversations for memory context
+
+CREATE TABLE IF NOT EXISTS ai_conversation_summary (
+    id SERIAL PRIMARY KEY,
+    conversation_id INTEGER NOT NULL UNIQUE REFERENCES ai_chat_conversations(id) ON DELETE CASCADE,
+    user_id INTEGER NOT NULL REFERENCES users(id) ON DELETE CASCADE,
+    summary TEXT NOT NULL,
+    key_topics JSONB DEFAULT '[]',
+    created_at TIMESTAMP DEFAULT NOW(),
+    updated_at TIMESTAMP DEFAULT NOW()
+);
+
+CREATE INDEX idx_ai_conv_summary_user ON ai_conversation_summary(user_id, created_at DESC);
+
+GRANT ALL ON TABLE ai_conversation_summary TO nordabiz_app;
+GRANT USAGE, SELECT ON SEQUENCE ai_conversation_summary_id_seq TO nordabiz_app;