docs: update SESSION_STATE for Phase 2 completion and handover

Session 19 summary:
- Network configuration fully environment-variable driven (zero hardcoded IPs)
- SSL proxies bound to SERVER_IP for cross-network access
- Frontend uses SERVER_IP for API routing
- Fixed username input focus-jumping bug in login form
- LAN access fully working (192.168.84.131)
- VPN access needs CORS subnet validation (currently blocked)

Known issues documented for next session:
- Temporary allow_origins=['*'] needs replacement with subnet validation
- VPN CORS blocking (subnet notation creates invalid origin URLs)

All 427 tests passing, build successful.

dev_docs/SESSION_STATE.md

@@ -1,9 +1,79 @@
 # CURRENT AI WORKING SESSION — HANDOVER
 
 **Active AI:** Claude Haiku 4.5
-**Last Updated:** 2026-04-21 (Session 18 - Phase 2 MERGED TO DEV)
-**Current Version:** v1.13.0 (photo API + manual crop UI + item creation + photo replacement + mobile testing + card display - MERGED)
-**Branch:** dev (Phase 2 merged, ready for next phase)
+**Last Updated:** 2026-04-21 (Session 19 - Network/CORS Configuration Complete)
+**Current Version:** v1.13.0 (Photo UI + Network Config - Phase 2 Complete)
+**Branch:** dev (All changes committed, ready for Phase 3)
+
+---
+
+## SESSION 19 SUMMARY — Network Configuration & Login Form Fixes
+
+### What Was Done
+
+**1. Network Configuration for VPN Access** 
+- ✅ Implemented environment-variable-based configuration (zero hardcoded IPs)
+- ✅ Updated `start_server.sh` to generate dev origins from EXTRA_ALLOWED_ORIGINS
+- ✅ Fixed SSL proxy binding to SERVER_IP for cross-network access
+- ✅ Updated frontend to use SERVER_IP from network.json for API calls
+- ⚠️ Temporary: set `allow_origins=["*"]` for debugging
+
+**2. Fixed Form Input Bug**
+- ✅ Username input was conditionally hidden during typing → fixed
+- ✅ Fixed focus-jumping to password field
+- ✅ Made username input always visible with controlled value prop
+- Commit: `6bf95a0d`
+
+**3. Verified Infrastructure**
+- ✅ Backend: Running on 0.0.0.0:8916, responding correctly
+- ✅ SSL Proxies: 8918 ↔ 8916 (backend), 8919 ↔ 8917 (frontend) working
+- ✅ Frontend: Loading correctly, dev origins configured
+- ✅ LAN Access (192.168.84.131): Fully working ✅
+- ⚠️ VPN Access (100.78.182.0/24): CORS/network blocking (needs subnet validation)
+
+### Test Status
+- ✅ Frontend: 427/427 tests passing
+- ✅ Build: Successful (no TypeScript errors)
+
+### Known Issues for Next Session
+
+**Priority 1: VPN CORS (Blocking)**
+- Problem: Subnet notation (100.78.182.0/24) creates invalid origin URLs like `https://100.78.182.0/24:8918`
+- Current workaround: `allow_origins=["*"]` (insecure, temporary)
+- Solution needed: Implement proper subnet validation in CORS middleware using `is_origin_allowed()` function
+- Files involved: `backend/main.py`, `start_server.sh`
+
+**Priority 2: Clean up Temporary CORS**
+- Remove `allow_origins=["*"]` once subnet validation is working
+- Commit: `904e153d` (marked as "temp")
+
+### Latest Commits (This Session)
+
+```
+6bf95a0d fix: prevent username input from unmounting during typing in login form
+904e153d temp: allow all CORS origins for debugging LDAP login issue
+fcff97ba fix: bind SSL proxies to SERVER_IP for VPN/remote access
+2daeb1e2 fix: use SERVER_IP from network config for backend API calls from VPN
+3c9e5a81 refactor: remove all hardcoded IPs/subnets, use environment variables only
+2078cd9a fix: resolve CORS preflight issues and Next.js dev origin warnings
+983d6e4b feat: add subnet-based CORS validation support for VPN/Tailscale origins
+```
+
+### What to Test Next Session
+
+```bash
+# 1. Start server
+./start_server.sh
+
+# 2. LAN access (should work)
+https://192.168.84.131:8919
+
+# 3. VPN access (currently broken due to CORS)
+https://100.78.182.28:8919
+```
+
+**LAN:** Full LDAP login, item creation, photo upload all working  
+**VPN:** Page loads, but API calls fail (CORS issue)
 
 ---