feat: beta feedback widget — frictionless in-session feedback

Full-stack beta feedback system:

Backend:
- BetaFeedback model with reaction, category, text, page context
- POST /feedback/beta (any auth user), GET /feedback/beta (admin, filtered)
- Alembic migration 065 with indexes on user_id, reaction, created_at

Frontend:
- Persistent "Feedback" tab on right edge of all authenticated pages
- Slide-out panel: quick reaction (👍😐👎), category pills, optional text
- Auto-captures page URL and FlowPilot session ID
- Hidden on mobile (<640px), closes on Escape/outside click
- Shows "Thanks!" confirmation then auto-closes

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

backend/app/models/__init__.py

@@ -49,6 +49,7 @@ from .notification import Notification
 from .psa_activity_log import PsaActivityLog
 from .file_upload import FileUpload
 from .ai_session_embedding import AISessionEmbedding
+from .beta_feedback import BetaFeedback
 
 __all__ = [
     "User",
@@ -112,4 +113,5 @@ __all__ = [
     "PsaActivityLog",
     "FileUpload",
     "AISessionEmbedding",
+    "BetaFeedback",
 ]

backend/app/models/beta_feedback.py

@@ -0,0 +1,20 @@
+import uuid
+from datetime import datetime, timezone
+from typing import Optional
+from sqlalchemy import String, Text, DateTime, ForeignKey, func
+from sqlalchemy.orm import Mapped, mapped_column
+from sqlalchemy.dialects.postgresql import UUID
+from app.core.database import Base
+
+
+class BetaFeedback(Base):
+    __tablename__ = "beta_feedback"
+
+    id: Mapped[uuid.UUID] = mapped_column(UUID(as_uuid=True), primary_key=True, default=uuid.uuid4)
+    user_id: Mapped[uuid.UUID] = mapped_column(UUID(as_uuid=True), ForeignKey("users.id", ondelete="CASCADE"), nullable=False)
+    reaction: Mapped[str] = mapped_column(String(10), nullable=False)  # 'positive', 'neutral', 'negative'
+    category: Mapped[Optional[str]] = mapped_column(String(30), nullable=True)  # 'bug', 'feature', 'confusing', 'praise'
+    text: Mapped[Optional[str]] = mapped_column(Text, nullable=True)
+    page_url: Mapped[Optional[str]] = mapped_column(String(500), nullable=True)
+    session_id: Mapped[Optional[str]] = mapped_column(String(100), nullable=True)  # FlowPilot session ID if applicable
+    created_at: Mapped[datetime] = mapped_column(DateTime(timezone=True), server_default=func.now())