feat: Add project_context tool and CWD auto-detection

New features:
- detectProjectFromCwd(): Maps directory paths to project keys
- project_context: Returns project, tasks, epics, lock status
- Auto-detection for 18 known projects (ST, VPN, OWUI, etc.)
- Falls back to extracting from Apps/X or Infrastructure/X paths

Use project_context at session start to see only relevant tasks.

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

src/tools/index.ts

@@ -272,4 +272,12 @@ export const toolDefinitions = [
       },
     },
   },
+  {
+    name: 'project_context',
+    description: 'Get project context from current directory - returns detected project, open tasks, epics, and lock status. Use at session start.',
+    inputSchema: {
+      type: 'object',
+      properties: {},
+    },
+  },
 ];