Split webui into Flask blueprints and data domain modules

- Split app.py (66 routes) into 3 blueprints: pages (public), api (JSON), admin (@admin_required)
- Split data.py (4,360 LOC) into 7 domain modules: drafts, authors, ratings, gaps, analysis, search, proposals
- Add data/__init__.py re-exporting all public functions for backward compatibility
- Add custom 404/500 error pages matching dark theme
- Add request timing logging via before_request/after_request hooks
- Refactor app.py into create_app() factory pattern
- All 106 tests pass, all 66 routes preserved

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

src/webui/data/__init__.py

@@ -0,0 +1,97 @@
+"""Data access layer for the web dashboard.
+
+Thin wrapper around ietf_analyzer.db.Database that returns plain dicts
+ready for JSON serialization or Jinja2 template rendering.
+
+All public functions are re-exported here for backward compatibility:
+    from webui.data import get_overview_stats
+"""
+from __future__ import annotations
+
+# Shared utilities
+from webui.data._shared import get_db, _cached, _extract_month  # noqa: F401
+
+# Drafts
+from webui.data.drafts import (  # noqa: F401
+    OverviewStats,
+    DraftListItem,
+    DraftsPage,
+    get_overview_stats,
+    get_category_counts,
+    get_category_summary,
+    get_drafts_page,
+    get_draft_detail,
+    get_generated_drafts,
+    read_generated_draft,
+)
+
+# Authors
+from webui.data.authors import (  # noqa: F401
+    AuthorInfo,
+    AuthorNetworkNode,
+    AuthorNetworkEdge,
+    AuthorCluster,
+    AuthorNetwork,
+    get_top_authors,
+    get_org_data,
+    get_coauthor_network,
+    get_cross_org_data,
+    get_author_network_full,
+)
+
+# Ratings
+from webui.data.ratings import (  # noqa: F401
+    get_rating_distributions,
+    get_category_radar_data,
+    get_score_histogram,
+    get_false_positive_profile,
+)
+
+# Gaps
+from webui.data.gaps import (  # noqa: F401
+    get_all_gaps,
+    get_gap_detail,
+)
+
+# Analysis & Visualization
+from webui.data.analysis import (  # noqa: F401
+    TimelineData,
+    SimilarityGraphStats,
+    SimilarityGraph,
+    CitationGraphStats,
+    CitationGraph,
+    MonitorCost,
+    MonitorPipeline,
+    MonitorStatus,
+    get_ideas_by_type,
+    get_timeline_data,
+    get_similarity_graph,
+    get_idea_clusters,
+    get_timeline_animation_data,
+    get_monitor_status,
+    get_citation_graph,
+    get_landscape_tsne,
+    get_comparison_data,
+    get_architecture,
+    get_idea_analysis,
+    get_trends_data,
+    get_complexity_data,
+    get_source_comparison,
+    get_citation_influence,
+    get_bcp_analysis,
+)
+
+# Search
+from webui.data.search import (  # noqa: F401
+    SearchResults,
+    global_search,
+    get_ask_search,
+    get_ask_synthesize,
+)
+
+# Proposals
+from webui.data.proposals import (  # noqa: F401
+    get_all_proposals,
+    get_proposal_detail,
+    get_proposals_for_gap,
+)