feat(notifications): follow modes, milestone alerts, notification enhancements

Follow Modes (neutral / pocket_veto / pocket_boost):
- Alembic migration 0013 adds follow_mode column to follows table
- FollowButton rewritten as mode-aware dropdown for bills; simple toggle for members/topics
- PATCH /api/follows/{id}/mode endpoint with validation
- Dispatcher filters pocket_veto follows (suppress new_document/new_amendment events)
- Dispatcher adds ntfy Actions header for pocket_boost follows

Change-driven (milestone) Alerts:
- New notification_utils.py with shared emit helpers and 30-min dedup
- congress_poller emits bill_updated events on milestone action text
- llm_processor replaced with shared emit util (also notifies member/topic followers)

Notification Enhancements:
- ntfy priority levels (high for bill_updated, default for others)
- Quiet hours (UTC): dispatcher holds events outside allowed window
- Digest mode (daily/weekly): send_notification_digest Celery beat task
- Notification history endpoint + Recent Alerts UI section
- Enriched following page (bill titles, member photos/details via sub-components)
- Follow mode test buttons in admin settings panel

Infrastructure:
- nginx: switch upstream blocks to set $variable proxy_pass so Docker DNS
  re-resolves upstream IPs after container rebuilds (valid=10s)
- TROUBLESHOOTING.md documenting common Docker/nginx/postgres gotchas

Authored-By: Jack Levy

backend/app/schemas/schemas.py

@@ -15,6 +15,12 @@ class NotificationSettingsResponse(BaseModel):
     ntfy_enabled: bool = False
     rss_enabled: bool = False
     rss_token: Optional[str] = None
+    # Digest
+    digest_enabled: bool = False
+    digest_frequency: str = "daily"  # daily | weekly
+    # Quiet hours (UTC hour integers 0-23, None = disabled)
+    quiet_hours_start: Optional[int] = None
+    quiet_hours_end: Optional[int] = None
 
     model_config = {"from_attributes": True}
 
@@ -27,6 +33,21 @@ class NotificationSettingsUpdate(BaseModel):
     ntfy_password: Optional[str] = None
     ntfy_enabled: Optional[bool] = None
     rss_enabled: Optional[bool] = None
+    digest_enabled: Optional[bool] = None
+    digest_frequency: Optional[str] = None
+    quiet_hours_start: Optional[int] = None
+    quiet_hours_end: Optional[int] = None
+
+
+class NotificationEventSchema(BaseModel):
+    id: int
+    bill_id: str
+    event_type: str
+    payload: Optional[Any] = None
+    dispatched_at: Optional[datetime] = None
+    created_at: datetime
+
+    model_config = {"from_attributes": True}
 
 
 class NtfyTestRequest(BaseModel):
@@ -37,6 +58,11 @@ class NtfyTestRequest(BaseModel):
     ntfy_password: str = ""
 
 
+class FollowModeTestRequest(BaseModel):
+    mode: str        # pocket_veto | pocket_boost
+    event_type: str  # new_document | new_amendment | bill_updated
+
+
 class NotificationTestResult(BaseModel):
     status: str  # "ok" | "error"
     detail: str
@@ -198,11 +224,16 @@ class FollowSchema(BaseModel):
     user_id: int
     follow_type: str
     follow_value: str
+    follow_mode: str = "neutral"
     created_at: datetime
 
     model_config = {"from_attributes": True}
 
 
+class FollowModeUpdate(BaseModel):
+    follow_mode: str
+
+
 # ── Settings ──────────────────────────────────────────────────────────────────
 
 # ── Auth ──────────────────────────────────────────────────────────────────────