chore(release): bump @mosaicstack/mosaic 0.0.38 -> 0.0.39

Batches the custom Pi harness (native HB + model self-report + tool, #602),
HB consistency (#599), watch/test fixes (#601), overlay composer (P5 #605),
and the constitution capstone (P6 #607: CONTRIBUTING + compliance matrix +
resident-budget gate). Tag v0.0.39-alpha closes the framework-constitution mission.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01RMoEx7hfdFGjUiCHuN1RRi

packages/mosaic/package.json

@@ -1,6 +1,6 @@
 {
   "name": "@mosaicstack/mosaic",
-  "version": "0.0.38",
+  "version": "0.0.39",
   "repository": {
     "type": "git",
     "url": "https://git.mosaicstack.dev/mosaicstack/stack.git",