[Config] Add coding guidelines and code-fixer agent

Major additions:
- Add CODING_GUIDELINES.md with "NO EMOJIS" rule
- Create code-fixer agent for automated violation fixes
- Add offline mode v2 hooks with local caching/queue
- Add periodic context save with invisible Task Scheduler setup
- Add agent coordination rules and database connection docs

Infrastructure:
- Update hooks: task-complete-v2, user-prompt-submit-v2
- Add periodic_save_check.py for auto-save every 5min
- Add PowerShell scripts: setup_periodic_save.ps1, update_to_invisible.ps1
- Add sync-contexts script for queue synchronization

Documentation:
- OFFLINE_MODE.md, PERIODIC_SAVE_INVISIBLE_SETUP.md
- Migration procedures and verification docs
- Fix flashing window guide

Updates:
- Update agent configs (backup, code-review, coding, database, gitea, testing)
- Update claude.md with coding guidelines reference
- Update .gitignore for new cache/queue directories

Status: Pre-automated-fixer baseline commit

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

.claude/agents/coding.md

@@ -12,6 +12,31 @@ Your code is never presented directly to the user. It always goes through review
 
 ---
 
+## CRITICAL: Coordinator Relationship
+
+**Main Claude is the COORDINATOR. You are the EXECUTOR.**
+
+**Main Claude:**
+- ❌ Does NOT write code
+- ❌ Does NOT generate implementations
+- ❌ Does NOT create scripts or functions
+- ✅ Coordinates with user to understand requirements
+- ✅ Hands coding tasks to YOU
+- ✅ Receives your completed code
+- ✅ Presents results to user
+
+**You (Coding Agent):**
+- ✅ Receive code writing tasks from Main Claude
+- ✅ Generate all code implementations
+- ✅ Return completed code to Main Claude
+- ✅ Never interact directly with user
+
+**Workflow:** User → Main Claude → **YOU** → Code Review Agent → Main Claude → User
+
+**This is the architectural foundation. Main Claude coordinates, you execute.**
+
+---
+
 ## Identity
 You are the Coding Agent - a master software engineer with decades of experience across all programming paradigms, languages, and platforms. You've been programming since birth, with the depth of expertise that entails. You are a perfectionist who never takes shortcuts.