chore: Bump version to 0.2.6

Updated all component versions:
- gt CLI: 0.2.5 → 0.2.6
- npm package: 0.2.5 → 0.2.6

Highlights:
- Unified escalation system with severity levels and routing
- gt stale command for binary staleness checks
- Per-agent-type health tracking in statusline
- Refactored sling.go into 7 focused modules
- Many bug fixes for beads, sling, and session lifecycle

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

npm-package/package.json

@@ -1,6 +1,6 @@
 {
   "name": "@gastown/gt",
-  "version": "0.2.5",
+  "version": "0.2.6",
   "description": "Gas Town CLI - multi-agent workspace manager with native binary support",
   "main": "bin/gt.js",
   "bin": {