refactor: rename hf_yolov8 → yolo11 across codebase

feat(segmentation): add YSAM2 variants and mission-aware detector mapping

refactor(gsam2): make SAM2 detector-agnostic

feat(frontend): improve UI for detection and chat interaction

Remove SAM3 and standardize segmentation on Grounded-SAM2

Rename UI terms: Reason->Detect, Engage->Track

Redesign track cards with inline features, remove separate features panel, clean up overlays

fix: Remove chat emojis, improve tracker GPT metadata sync

feat: Add threat chat feature for Q&A about detected threats

chore(frontend): Remove Engagement Policy section and fix engage button

chore(frontend): Remove unused UI sections - radar, intel summary, HEL knobs, atmosphere, and trade space

chore(forensics): finalize verification and trace validation\n\n- Fix unreachable background reasoning in inference.py\n- Enable enabling GPT reasoning by default in frontend\n- Verify correct data mapping for 15 naval fields\n- Clean up legacy code paths and ensure backward compatibility

Add military-style radar with helicopter demo mode

Refine overlays: Hide on first frame and remove speed from labels

feat: Continuous object tracking, speed estimation, and overlay syncing

Refactor frontend into modular ES modules in frontend/ folder