Update development environment configurations

Major improvements to Neovim setup:
- Replace NERDTree with nvim-tree for better Git integration
- Add Biome LSP for JavaScript/TypeScript linting
- Improve statuscolumn formatting with better number spacing
- Add markdown preview with Mermaid diagram support
- Update indent guide styling for subtle visual cues

Configuration changes:
- Add code quality standards documentation (6 Golden Rules)
- Update Claude Code settings with schema and feedback state
- Remove deprecated Zed agent configuration
- Switch to language server formatting over Prettier
- Remove unused Homebrew packages (Pieces)
- Fix out-of-store symlink for Claude settings

Author: svnlto

CLAUDE.md

@@ -129,3 +129,13 @@ Located in `common/claude-code/`, this provides:
 - Tailscale for secure cloud connectivity
 - Proper credential management for AWS profiles
 - Isolated development environments prevent host contamination
+
+## Code Quality Standards
+
+**6 Golden Rules for Clean Code** (Neo Kim):
+1. **SOC** - Separation of concerns
+2. **DYC** - Document your code
+3. **DRY** - Don't repeat yourself
+4. **KISS** - Keep it simple stupid
+5. **TDD** - Test driven development
+6. **YAGNI** - You ain't gonna need it

common/claude-code/CLAUDE.md

@@ -75,8 +75,17 @@ Would you like me to [improvement suggestion]?"
 </communication_patterns>
 
 <implementation_standards>
-<code_quality>
+  <code_quality>
 
+**6 Golden Rules for Clean Code**:
+1. **SOC** - Separation of concerns
+2. **DYC** - Document your code
+3. **DRY** - Don't repeat yourself
+4. **KISS** - Keep it simple stupid
+5. **TDD** - Test driven development
+6. **YAGNI** - You ain't gonna need it
+
+**Additional Quality Standards**:
 - **Clarity over cleverness**: Write obvious, readable code
 - **Explicit over implicit**: Make intentions clear
 - **Simple over abstract**: Avoid unnecessary complexity

common/claude-code/default.nix

@@ -17,8 +17,9 @@
     NPM_CONFIG_PREFIX = "$HOME/.npm-global";
   };
 
-  # Create and manage ~/.claude directory
-  home.file.".claude/settings.json".source = ./settings.json;
+  # Create writable settings.json using out-of-store symlink
+  home.file.".claude/settings.json".source =
+    config.lib.file.mkOutOfStoreSymlink "${config.home.homeDirectory}/.config/nix/common/claude-code/settings.json";
   home.file.".claude/CLAUDE.md".source = ./CLAUDE.md;
 
   # Combine local commands with linear commands

common/claude-code/settings.json

@@ -1,10 +1,14 @@
 {
-  "model": "claude-sonnet-4-20250514",
+  "$schema": "https://json.schemastore.org/claude-code-settings.json",
   "includeCoAuthoredBy": false,
+  "model": "sonnet",
   "enableAllProjectMcpServers": true,
   "enabledMcpjsonServers": [
     "code-reasoning",
     "sequential-thinking",
     "context7"
-  ]
+  ],
+  "feedbackSurveyState": {
+    "lastShownTime": 1754125509075
+  }
 }