feat: Add Sequential Thinking to Code Review + Frontend Validation

Enhanced code review and frontend validation with intelligent triggers:

Code Review Agent Enhancement:
- Added Sequential Thinking MCP integration for complex issues
- Triggers on 2+ rejections or 3+ critical issues
- New escalation format with root cause analysis
- Comprehensive solution strategies with trade-off evaluation
- Educational feedback to break rejection cycles
- Files: .claude/agents/code-review.md (+308 lines)
- Docs: CODE_REVIEW_ST_ENHANCEMENT.md, CODE_REVIEW_ST_TESTING.md

Frontend Design Skill Enhancement:
- Automatic invocation for ANY UI change
- Comprehensive validation checklist (200+ checkpoints)
- 8 validation categories (visual, interactive, responsive, a11y, etc.)
- 3 validation levels (quick, standard, comprehensive)
- Integration with code review workflow
- Files: .claude/skills/frontend-design/SKILL.md (+120 lines)
- Docs: UI_VALIDATION_CHECKLIST.md (462 lines), AUTOMATIC_VALIDATION_ENHANCEMENT.md (587 lines)

Settings Optimization:
- Repaired .claude/settings.local.json (fixed m365 pattern)
- Reduced permissions from 49 to 33 (33% reduction)
- Removed duplicates, sorted alphabetically
- Created SETTINGS_PERMISSIONS.md documentation

Checkpoint Command Enhancement:
- Dual checkpoint system (git + database)
- Saves session context to API for cross-machine recall
- Includes git metadata in database context
- Files: .claude/commands/checkpoint.md (+139 lines)

Decision Rationale:
- Sequential Thinking MCP breaks rejection cycles by identifying root causes
- Automatic frontend validation catches UI issues before code review
- Dual checkpoints enable complete project memory across machines
- Settings optimization improves maintainability

Total: 1,200+ lines of documentation and enhancements

Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>

imported-conversations/auto-claude-variants/ui-backend/9b34c95d-e622-4d54-b928-8a3b991a4ce0/subagents/agent-a265dc1.jsonl

@@ -0,0 +1,2 @@
+{"parentUuid":null,"isSidechain":true,"userType":"external","cwd":"C:\\Users\\MikeSwanson\\AppData\\Local\\Programs\\auto-claude-ui\\resources\\backend","sessionId":"9b34c95d-e622-4d54-b928-8a3b991a4ce0","version":"2.1.5","gitBranch":"","agentId":"a265dc1","type":"user","message":{"role":"user","content":"Warmup"},"uuid":"966b0528-a1b2-4526-a231-1c5645b2db9b","timestamp":"2026-01-12T18:50:45.168Z"}
+{"parentUuid":"966b0528-a1b2-4526-a231-1c5645b2db9b","isSidechain":true,"userType":"external","cwd":"C:\\Users\\MikeSwanson\\AppData\\Local\\Programs\\auto-claude-ui\\resources\\backend","sessionId":"9b34c95d-e622-4d54-b928-8a3b991a4ce0","version":"2.1.5","gitBranch":"","agentId":"a265dc1","message":{"model":"claude-haiku-4-5-20251001","id":"msg_01Tt3SaLC3CzB4k9cHFaYZ6B","type":"message","role":"assistant","content":[{"type":"text","text":"I'm ready to help! I'm Claude Code, a read-only file search specialist. I can help you explore and analyze codebases efficiently.\n\nI'm currently in the directory: `C:\\Users\\MikeSwanson\\AppData\\Local\\Programs\\auto-claude-ui\\resources\\backend`\n\nHere's what I can do for you:\n\n- **Search for files** using glob patterns (e.g., find all `.js` files in a specific folder)\n- **Search file contents** using regex patterns to find specific code, functions, or strings\n- **Read and analyze** specific files you point me to\n- **Explore code structure** and understand how different parts of your codebase fit together\n\nJust let me know what you'd like to find or explore! You can ask me to:\n- Find files matching a pattern\n- Search for specific functions, variables, or code patterns\n- Explore the structure of a particular directory\n- Analyze code in specific files\n\nWhat would you like to search for?"}],"stop_reason":null,"stop_sequence":null,"usage":{"input_tokens":2,"cache_creation_input_tokens":0,"cache_read_input_tokens":10550,"cache_creation":{"ephemeral_5m_input_tokens":0,"ephemeral_1h_input_tokens":0},"output_tokens":225,"service_tier":"standard"}},"requestId":"req_011CX3zBTL4fybRkZJhQgPPA","type":"assistant","uuid":"d89539a9-713f-4d31-814d-85b540f2ae1d","timestamp":"2026-01-12T18:50:48.354Z"}

imported-conversations/auto-claude-variants/ui-backend/9b34c95d-e622-4d54-b928-8a3b991a4ce0/subagents/agent-a3f6222.jsonl

@@ -0,0 +1,2 @@
+{"parentUuid":null,"isSidechain":true,"userType":"external","cwd":"C:\\Users\\MikeSwanson\\AppData\\Local\\Programs\\auto-claude-ui\\resources\\backend","sessionId":"9b34c95d-e622-4d54-b928-8a3b991a4ce0","version":"2.1.5","gitBranch":"","agentId":"a3f6222","type":"user","message":{"role":"user","content":"Warmup"},"uuid":"073524e6-ea58-4490-805e-e0d191464cfd","timestamp":"2026-01-12T18:50:45.265Z"}
+{"parentUuid":"073524e6-ea58-4490-805e-e0d191464cfd","isSidechain":true,"userType":"external","cwd":"C:\\Users\\MikeSwanson\\AppData\\Local\\Programs\\auto-claude-ui\\resources\\backend","sessionId":"9b34c95d-e622-4d54-b928-8a3b991a4ce0","version":"2.1.5","gitBranch":"","agentId":"a3f6222","message":{"model":"claude-sonnet-4-5-20250929","id":"msg_01MtGRVfxRf9cpmKcYNY9Pfy","type":"message","role":"assistant","content":[{"type":"text","text":"Hello! I'm ready to help you explore codebases and design implementation plans.\n\nAs a reminder, I'm operating in **READ-ONLY mode**, which means I can:\n- Explore the codebase using Glob, Grep, and Read\n- Analyze existing patterns and architecture\n- Design detailed implementation plans\n- Identify critical files and dependencies\n\nBut I **cannot**:\n- Create, modify, or delete files\n- Run commands that change system state\n- Install packages or dependencies\n\nI'm currently in the directory: `C:\\Users\\MikeSwanson\\AppData\\Local\\Programs\\auto-claude-ui\\resources\\backend`\n\nWhat would you like me to help you plan or explore?"}],"stop_reason":null,"stop_sequence":null,"usage":{"input_tokens":2,"cache_creation_input_tokens":0,"cache_read_input_tokens":10669,"cache_creation":{"ephemeral_5m_input_tokens":0,"ephemeral_1h_input_tokens":0},"output_tokens":160,"service_tier":"standard"}},"requestId":"req_011CX3zBTrp9cEBoKRLV2YJY","type":"assistant","uuid":"e35b8a3b-5fb2-47ca-9297-81f089437338","timestamp":"2026-01-12T18:50:50.401Z"}

imported-conversations/auto-claude-variants/ui-backend/9b34c95d-e622-4d54-b928-8a3b991a4ce0/subagents/agent-a5b891a.jsonl

@@ -0,0 +1,2 @@
+{"parentUuid":null,"isSidechain":true,"userType":"external","cwd":"C:\\Users\\MikeSwanson\\AppData\\Local\\Programs\\auto-claude-ui\\resources\\backend","sessionId":"9b34c95d-e622-4d54-b928-8a3b991a4ce0","version":"2.1.5","gitBranch":"","agentId":"a5b891a","type":"user","message":{"role":"user","content":"Warmup"},"uuid":"bfe2d26d-8bdc-4efd-b2dc-4461d7d5da4d","timestamp":"2026-01-12T18:50:45.521Z"}
+{"parentUuid":"bfe2d26d-8bdc-4efd-b2dc-4461d7d5da4d","isSidechain":true,"userType":"external","cwd":"C:\\Users\\MikeSwanson\\AppData\\Local\\Programs\\auto-claude-ui\\resources\\backend","sessionId":"9b34c95d-e622-4d54-b928-8a3b991a4ce0","version":"2.1.5","gitBranch":"","agentId":"a5b891a","message":{"model":"claude-sonnet-4-5-20250929","id":"msg_01STJETuFTPdCxrsKEpvR21t","type":"message","role":"assistant","content":[{"type":"text","text":"I'm ready to help you execute bash commands. I'm warmed up and standing by to assist with any command execution tasks you need.\n\nWhat would you like me to do?"}],"stop_reason":null,"stop_sequence":null,"usage":{"input_tokens":2,"cache_creation_input_tokens":0,"cache_read_input_tokens":4062,"cache_creation":{"ephemeral_5m_input_tokens":0,"ephemeral_1h_input_tokens":0},"output_tokens":40,"service_tier":"standard"}},"requestId":"req_011CX3zBTzzVQKThzkBEK8gd","type":"assistant","uuid":"765b9eeb-51c6-4892-a60b-126af661b387","timestamp":"2026-01-12T18:50:48.594Z"}