docs: update CURRENT-STATE.md and stack priorities — Search & Evidence complete

Evidence: S3 storage, clipboard paste uploads, exports integration.
Search: structured filters, FTS, Command Palette, semantic similar sessions.

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

CURRENT-STATE.md

@@ -6,7 +6,7 @@
 
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-## Active Phase: Phase 5 - Analytics Enhancement (Complete)
+## Active Phase: Search & Evidence Features (Complete)
 
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@@ -130,6 +130,25 @@
 - Enhanced PSA metrics: time entries, hours logged, push success funnel, daily trend chart
 - 13 new backend tests for coverage and flow quality endpoints
 
+### Search & Recall + Evidence-Rich Sessions (Complete)
+
+**Evidence:**
+- Railway Object Storage (S3-compatible) integration via boto3
+- file_uploads model with upload/download/list/delete API endpoints
+- RichTextInput component: clipboard paste (Ctrl+V) and drag-and-drop for images
+- Wired into FlowPilot intake, free-text responses, and escalation modal
+- Evidence included in all 5 export formats (markdown, text, HTML, PSA, PDF)
+- 15 backend tests for upload endpoints
+
+**Search:**
+- Structured filters on AI sessions: problem_domain, matched_flow, confidence_tier, ticket_id, date range
+- Filter bar UI on Session History page (AI Sessions tab)
+- PostgreSQL full-text search via generated tsvector column + GIN index on ai_sessions
+- Command Palette extended with AI session search results
+- Voyage AI semantic embeddings on ai_session_embeddings table (pgvector cosine similarity)
+- Similar sessions endpoint: GET /ai-sessions/{id}/similar
+- Similar Sessions sidebar component in FlowPilot session view
+
 ### Security Hardening (Phases A-D Complete)
 - Registration role hardcoded to `engineer`
 - HTML export XSS fix (html.escape)