Phase 1 MVP - Complete implementation

- Auth: register, login, JWT with refresh tokens, blocklist
- Projects/Folders/Documents CRUD with soft deletes
- Tags CRUD and assignment
- FTS5 search with highlights and tag filtering
- ADR-001, ADR-002, ADR-003 compliant
- Security fixes applied (JWT_SECRET_KEY, exception handler, cookie secure)
- 25 tests passing

app/schemas/auth.py

@@ -0,0 +1,32 @@
+from datetime import datetime
+
+from pydantic import BaseModel, Field
+
+
+class AgentCreate(BaseModel):
+    username: str = Field(..., min_length=3, max_length=50)
+    password: str = Field(..., min_length=6)
+
+
+class AgentResponse(BaseModel):
+    id: str
+    username: str
+    role: str
+    created_at: datetime
+
+    model_config = {"from_attributes": True}
+
+
+class AgentLogin(BaseModel):
+    username: str
+    password: str
+
+
+class TokenResponse(BaseModel):
+    access_token: str
+    token_type: str = "bearer"
+
+
+class RefreshResponse(BaseModel):
+    access_token: str
+    token_type: str = "bearer"