Add multi-user auth, background generation, and chat UX improvements

Phase 5: Multi-user authentication with session cookies, bcrypt passwords,
first-user-is-admin pattern, per-user data isolation, backup/restore,
Docker Swarm production stack with secrets and network isolation.

Phase 5.1: Chat UX improvements:
- Background generation architecture (GenerationBuffer + asyncio task)
  with SSE fan-out, reconnect support, and periodic DB flushes
- LLM-generated conversation titles (first exchange + every 10th message)
- Stop generation button with cancel_event and partial content preservation
- Relative timestamps in sidebar (5m ago, 3h ago, then dates)
- Empty chat auto-cleanup on navigation away
- Save-as-note uses LLM for title generation, tags notes with "chat"
- Summarize-as-note also tags with "chat"

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

src/fabledassistant/models/__init__.py

@@ -14,3 +14,4 @@ class Base(DeclarativeBase):
 from fabledassistant.models.note import Note, TaskPriority, TaskStatus  # noqa: E402, F401
 from fabledassistant.models.conversation import Conversation, Message  # noqa: E402, F401
 from fabledassistant.models.setting import Setting  # noqa: E402, F401
+from fabledassistant.models.user import User  # noqa: E402, F401

src/fabledassistant/models/conversation.py

@@ -11,6 +11,9 @@ class Conversation(Base):
     __tablename__ = "conversations"
 
     id: Mapped[int] = mapped_column(primary_key=True)
+    user_id: Mapped[int | None] = mapped_column(
+        Integer, ForeignKey("users.id", ondelete="CASCADE"), nullable=True
+    )
     title: Mapped[str] = mapped_column(Text, default="")
     model: Mapped[str] = mapped_column(Text, default="")
     created_at: Mapped[datetime] = mapped_column(
@@ -30,6 +33,7 @@ class Conversation(Base):
 
     __table_args__ = (
         Index("ix_conversations_updated_at", "updated_at"),
+        Index("ix_conversations_user_id", "user_id"),
     )
 
     def to_dict(self) -> dict:
@@ -57,6 +61,7 @@ class Message(Base):
     )
     role: Mapped[str] = mapped_column(Text)
     content: Mapped[str] = mapped_column(Text, default="")
+    status: Mapped[str] = mapped_column(Text, default="complete")
     context_note_id: Mapped[int | None] = mapped_column(
         Integer, ForeignKey("notes.id", ondelete="SET NULL"), nullable=True
     )
@@ -76,6 +81,7 @@ class Message(Base):
             "conversation_id": self.conversation_id,
             "role": self.role,
             "content": self.content,
+            "status": self.status,
             "context_note_id": self.context_note_id,
             "created_at": self.created_at.isoformat(),
         }

src/fabledassistant/models/note.py

@@ -1,7 +1,7 @@
 import enum
 from datetime import date, datetime, timezone
 
-from sqlalchemy import Date, DateTime, Index, Text
+from sqlalchemy import Date, DateTime, ForeignKey, Index, Integer, Text
 from sqlalchemy.dialects.postgresql import ARRAY
 from sqlalchemy.orm import Mapped, mapped_column
 
@@ -25,6 +25,9 @@ class Note(Base):
     __tablename__ = "notes"
 
     id: Mapped[int] = mapped_column(primary_key=True)
+    user_id: Mapped[int | None] = mapped_column(
+        Integer, ForeignKey("users.id", ondelete="CASCADE"), nullable=True
+    )
     title: Mapped[str] = mapped_column(Text, default="")
     body: Mapped[str] = mapped_column(Text, default="")
     tags: Mapped[list[str]] = mapped_column(ARRAY(Text), default=list)
@@ -47,6 +50,7 @@ class Note(Base):
         Index("ix_notes_tags", "tags", postgresql_using="gin"),
         Index("ix_notes_status", "status"),
         Index("ix_notes_title", "title"),
+        Index("ix_notes_user_id", "user_id"),
     )
 
     @property

src/fabledassistant/models/setting.py

@@ -1,4 +1,4 @@
-from sqlalchemy import Text
+from sqlalchemy import ForeignKey, Integer, Text
 from sqlalchemy.orm import Mapped, mapped_column
 
 from fabledassistant.models import Base
@@ -7,6 +7,9 @@ from fabledassistant.models import Base
 class Setting(Base):
     __tablename__ = "settings"
 
+    user_id: Mapped[int] = mapped_column(
+        Integer, ForeignKey("users.id", ondelete="CASCADE"), primary_key=True
+    )
     key: Mapped[str] = mapped_column(Text, primary_key=True)
     value: Mapped[str] = mapped_column(Text, default="")
 

src/fabledassistant/models/user.py

@@ -0,0 +1,32 @@
+from datetime import datetime, timezone
+
+from sqlalchemy import DateTime, Index, Text
+from sqlalchemy.orm import Mapped, mapped_column
+
+from fabledassistant.models import Base
+
+
+class User(Base):
+    __tablename__ = "users"
+
+    id: Mapped[int] = mapped_column(primary_key=True)
+    username: Mapped[str] = mapped_column(Text, unique=True, nullable=False)
+    email: Mapped[str | None] = mapped_column(Text, nullable=True)
+    password_hash: Mapped[str] = mapped_column(Text, nullable=False)
+    role: Mapped[str] = mapped_column(Text, nullable=False, default="user")
+    created_at: Mapped[datetime] = mapped_column(
+        DateTime(timezone=True), default=lambda: datetime.now(timezone.utc)
+    )
+
+    __table_args__ = (
+        Index("ix_users_username", "username"),
+    )
+
+    def to_dict(self) -> dict:
+        return {
+            "id": self.id,
+            "username": self.username,
+            "email": self.email,
+            "role": self.role,
+            "created_at": self.created_at.isoformat(),
+        }