feat: ContentGuardianAgent, onboarding UX, Team Activity action wiring, docs, agent help modal

ContentGuardianAgent consolidation:
- Merge 3 duplicate classes into single source in specialized/content_guardian.py
- Watchdog audit_committee() with heuristic scoring, coverage gaps, overlaps, alerts
- Remove misleading rejection_rate() helper; use acceptance_rate directly
- Integrate audit + alerts + trend signals into today_workflow_service.py

Team Activity page:
- QualityAuditPanel: health ring, per-agent critiques, coverage gaps, overlaps
- TrendSignalsPanel: opportunity cards with urgency/impact/coverage bars
- AlertBanner: persistent dismiss via POST /alerts/{id}/mark-read
- AgentHelpModal: dialog showing all 8 agents with descriptions, tools, schedule
- QualityAuditPanel action buttons: Fill gap -> /content-planning, Resolve overlap, View CTA on alerts/issues
- TrendSignalsPanel action buttons: Create content from this trend -> /blog-writer with trend context state

Onboarding system:
- Step 4 validation: no auto-pass via basic_ready; requires persona data or explicit progression
- Step 5 validation: logs warning on auto-pass without integration data
- OnboardingCompletionService: single DB session, transactional task creation, upsert pattern
- Business-without-website: nullable website_url on SIFIndexingTask and MarketTrendsTask
- DeepCompetitorAnalysisExecutor: 5-min timeout, 10-competitor cap, asyncio.wait_for
- Persona generation: async with 30s timeout, falls back to scheduler
- OnboardingProgressService.reset_onboarding(): resets session + pauses all DB tasks
- OnboardingControlService.reset_onboarding(): also cancels APScheduler jobs
- FinalStep TaskSchedulingPanel: shows scheduled/failed tasks after completion, 8s auto-redirect
- onboarding_completed agent activity event logged to feed

Documentation:
- docs-site/features/onboarding/: overview, steps, scheduler-tasks, technical-reference (4 pages)
- docs-site/mkdocs.yml: added Onboarding System nav section
- docs-site/features/sif-agents/: overview, agent-directory, committee-system, content-guardian (4 pages)
- docs-site/features/team-activity/: overview, quality-audit, trend-signals, alert-system (4 pages)
- docs-site/features/todays-workflow/: updated overview, technical-architecture, workflow-guide, api-reference

frontend/src/components/SEODashboard/SEODashboard.tsx

@@ -1,4 +1,5 @@
 import React, { useEffect, useRef, useState } from 'react';
+import { useLocation } from 'react-router-dom';
 import {
   Box,
   Container,
@@ -69,6 +70,7 @@ import { AdvertoolsInsights } from './components/AdvertoolsInsights';
 import SemanticHealthCard from './components/SemanticHealthCard';
 import SemanticInsights from './components/SemanticInsights';
 import KeywordGapAnalysis from './components/KeywordGapAnalysis';
+import ContentGapRadarCard from './components/ContentGapRadarCard';
 
 // Phase 2A: Enterprise SEO Analysis
 import SEOAnalysisController from './SEOAnalysisController';
@@ -118,7 +120,19 @@ const SEODashboard: React.FC = () => {
   
   // Dashboard Tab State for Enterprise Analysis
   const [dashboardTab, setDashboardTab] = useState<number>(0);
-  
+  const location = useLocation();
+
+  // Hash-based deep-link scroll (e.g. #content-gap-radar from workflow tasks)
+  useEffect(() => {
+    if (location.hash) {
+      const id = location.hash.replace('#', '');
+      const el = document.getElementById(id);
+      if (el) {
+        setTimeout(() => el.scrollIntoView({ behavior: 'smooth', block: 'center' }), 300);
+      }
+    }
+  }, [location.hash]);
+
   // Competitor analysis data from onboarding step 3
   const [competitorAnalysisData, setCompetitorAnalysisData] = useState<any>(null);
   const [deepCompetitorAnalysisData, setDeepCompetitorAnalysisData] = useState<any>(null);
@@ -933,6 +947,11 @@ const SEODashboard: React.FC = () => {
               {/* Keyword Gap Analysis */}
               <KeywordGapAnalysis />
 
+              {/* Content Gap Radar */}
+              <Box id="content-gap-radar">
+                <ContentGapRadarCard />
+              </Box>
+
               {/* Full Site Technical SEO Audit (from onboarding background job) */}
               {data.technical_seo_audit && (
                 <Box sx={{ mb: 4 }}>