feat(05-01): OpenTAKServer selected for TAK server implementation

- Comprehensive research of TAK-compatible open-source implementations
- Comparison of FreeTAKServer, OpenTAKServer, and TAK Product Center Server
- Selected OpenTAKServer for feature richness and Docker deployment support
- Documented research findings and implementation plan

.planning/STATE.md

@@ -7,17 +7,17 @@
 
 ## Current Position
 
-Phase: 4.2 of 5 (Internet Access & MCP)
-Plan: Complete
-Status: Complete - Web search capabilities tested and integrated
-Last activity: 2026-01-01 - Phase 4.2 completed, ready for Phase 5
+Phase: 5 of 7 (TAK Server Research & Selection)
+Plan: 1 of 3 complete
+Status: In progress - Phase 5.1 research completed
+Last activity: 2026-01-01 - Completed 05-01 research plan
 
-Progress: ▓▓▓▓▓▓▓░ 85%
+Progress: ▓▓▓▓▓▓█ 90%
 
 ## Performance Metrics
 
 **Velocity:**
-- Total plans completed: 13
+- Total plans completed: 14 (13 previous + 1 new)
 - Average duration: 0 min
 - Total execution time: 0.0 hours
 
@@ -28,7 +28,8 @@ Progress: ▓▓▓▓▓▓▓░ 85%
 | 1-3 | 8/8 | 8 | 0 |
 | 4.1 | 5/5 | 5 | 0 |
 | 4.2 | 2/2 | 2 | 0 |
-| 4.3-5 | 0/3 | 0 | N/A |
+| 5 | 1/3 | 1 | 10 min | 0 |
+| 6-7 | 0/6 | 0 | N/A |
 
 **Recent Trend:**
 - Last 5 plans: []
@@ -61,8 +62,22 @@ None yet.
 
 ## Session Continuity
 
-Last session: 2026-01-01 00:00
-Stopped at: Phase 4.1 completed - all changes committed logically
+Last session: 2026-01-01 23:15
+Stopped at: Phase 5.1 research completed - OpenTAKServer selected
 Resume file: None
 
-**Next Phase**: 4.2 - Continue with Internet Access & MCP implementation
+**Next Phase**: 5.2 - Compare features and select optimal solution
+
+## Accumulated Context
+
+### Decisions Made
+
+| Phase | Decision | Rationale |
+|-------|----------|-----------|
+| 1-3 | All phases completed | Foundational infrastructure in place |
+| 4 | Removed entirely | Not needed per user request |
+| 5.1 | Selected OpenTAKServer | Most feature-rich with web UI, video streaming, advanced authentication, and easy Docker deployment |
+
+### Deferred Issues
+
+None yet.