refactor: reorganize skill numbering, remove obsolete skills, rename shared libs

- Rename: 00→80 claude-settings-optimizer, 88→79 dintel-skill-update,
  92→81 mac-optimizer, 93→82 tui-design-template
- Rename: dintel-shared → _dintel-shared (consistent with _ourdigital-shared)
- Remove: 61-gtm-manager, 62-gtm-guardian (obsolete), 99_archive
- Update all dintel-* skill refs (114 occurrences across 31 files)
- Sync README.md, CLAUDE.md, AGENTS.md with new structure

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

custom-skills/80-claude-settings-optimizer/desktop/references/config-locations.md

@@ -0,0 +1,77 @@
+# Claude Desktop Configuration Locations
+
+## Primary Config File
+
+### macOS
+```
+~/Library/Application Support/Claude/claude_desktop_config.json
+```
+
+### Windows
+```
+%APPDATA%\Claude\claude_desktop_config.json
+```
+
+### Linux
+```
+~/.config/Claude/claude_desktop_config.json
+```
+
+## MCP Server Configuration Example
+
+```json
+{
+  "mcpServers": {
+    "playwright": {
+      "command": "npx",
+      "args": ["-y", "@anthropic-ai/mcp-playwright"],
+      "serverInstructions": "Browser automation. Use for: screenshots, page testing, DOM inspection. Keywords: browser, page, screenshot, navigate"
+    },
+    "notion": {
+      "command": "npx",
+      "args": ["-y", "@anthropic-ai/mcp-notion", "--token", "YOUR_TOKEN"],
+      "serverInstructions": "Notion workspace access. Use for: search pages, create content, update databases. Keywords: notion, page, database, workspace"
+    }
+  }
+}
+```
+
+## Key Fields
+
+| Field | Purpose | Token Impact |
+|-------|---------|--------------|
+| `command` | Executable path | Minimal |
+| `args` | Arguments | Minimal |
+| `serverInstructions` | Usage hints | Reduces discovery overhead |
+| `env` | Environment vars | None |
+
+## serverInstructions Best Practices
+
+**Good:**
+```json
+"serverInstructions": "File system access. Use for: read/write files, directory listing. Keywords: file, read, write, directory"
+```
+
+**Bad (too vague):**
+```json
+"serverInstructions": "Various file operations"
+```
+
+**Bad (too long):**
+```json
+"serverInstructions": "This MCP server provides comprehensive file system access capabilities including reading files, writing files, creating directories, listing directory contents, and more. It can be used for any operation that requires..."
+```
+
+## Viewing Current Configuration
+
+Ask user to run:
+
+**macOS/Linux:**
+```bash
+cat ~/Library/Application\ Support/Claude/claude_desktop_config.json | python3 -m json.tool
+```
+
+**Windows (PowerShell):**
+```powershell
+Get-Content "$env:APPDATA\Claude\claude_desktop_config.json" | ConvertFrom-Json | ConvertTo-Json -Depth 10
+```