Add load-cache-data agent skill for inspecting session file cache

.github/skills/README.md

@@ -32,6 +32,24 @@ Agent Skills are directories containing a `SKILL.md` file and optional supportin
 - Schema documentation references
 - Usage examples and troubleshooting guides
 
+### load-cache-data
+
+**Purpose**: Load and inspect the last 10 rows from the local session file cache to iterate with real data.
+
+**Use this skill when:**
+- Inspecting cached session file data
+- Debugging cache behavior or validation logic
+- Understanding what data is being cached
+- Working with real cached data for testing or development
+- Iterating on features that rely on cached statistics
+
+**Contents:**
+- Cache structure and storage location (VS Code globalState)
+- Methods for accessing and managing the cache
+- Example scripts demonstrating cache data access
+- Cache validation and lifecycle documentation
+- Integration with the extension's token tracking
+
 ## Using Agent Skills
 
 ### In VS Code

.github/skills/load-cache-data/README.md

@@ -0,0 +1,78 @@
+# Load Cache Data Skill - Quick Reference
+
+This skill provides tools and documentation for accessing the GitHub Copilot Token Tracker's local session file cache.
+
+## Quick Start
+
+```bash
+# Show last 10 cache entries (default)
+node .github/skills/load-cache-data/load-cache-data.js
+
+# Show last 5 entries
+node .github/skills/load-cache-data/load-cache-data.js --last 5
+
+# Output as JSON
+node .github/skills/load-cache-data/load-cache-data.js --json
+
+# Show help
+node .github/skills/load-cache-data/load-cache-data.js --help
+```
+
+## What This Skill Does
+
+1. **Reads actual cache data** - Loads real cache data from export files on disk
+2. **Multiple search locations** - Checks VS Code globalStorage, temp directory, and current directory
+3. **Helps debugging** - Inspect what's being cached and when
+4. **Supports development** - Iterate with real data structures when building features
+
+## Cache File Locations
+
+The script searches for cache export files in these locations (in order):
+
+**Windows:**
+- `%APPDATA%\Code\User\globalStorage\rajbos.copilot-token-tracker\cache.json`
+- `%TEMP%\copilot-token-tracker-cache.json`
+- `.\cache-export.json`
+
+**macOS:**
+- `~/Library/Application Support/Code/User/globalStorage/rajbos.copilot-token-tracker/cache.json`
+- `/tmp/copilot-token-tracker-cache.json`
+- `./cache-export.json`
+
+**Linux:**
+- `~/.config/Code/User/globalStorage/rajbos.copilot-token-tracker/cache.json`
+- `/tmp/copilot-token-tracker-cache.json`
+- `./cache-export.json`
+
+*Note: Also checks other VS Code variants (Insiders, Cursor, VSCodium, Code - Exploration)*
+
+## Important Note
+
+The extension stores its cache in VS Code's internal globalState (SQLite database `state.vscdb`), which is not directly accessible from external scripts. To use this skill with real data:
+
+1. **Export from extension**: Add functionality to export cache to disk
+2. **Export from tests**: Test code can write cache data to one of the expected locations
+3. **Manual export**: Extract cache from globalState and save to disk
+
+To access real cache data, use the extension's API:
+
+```typescript
+// In extension.ts or any file with access to ExtensionContext
+const cacheData = context.globalState.get<Record<string, SessionFileCache>>('sessionFileCache');
+const entries = Object.entries(cacheData || {});
+
+// Sort by most recent
+entries.sort((a, b) => (b[1].mtime || 0) - (a[1].mtime || 0));
+
+// Get last 10
+const last10 = entries.slice(0, 10);
+```
+
+## Full Documentation
+
+See [SKILL.md](./SKILL.md) for complete documentation including:
+- Cache structure details
+- Integration with extension code
+- Cache management methods
+- Troubleshooting guide
+- Example use cases