chore: bump mcpg to v0.2.29 in smoke-claude, smoke-codex, smoke-copilot

Set sandbox.mcp.version: v0.2.29 in frontmatter to test the GraphQL
fix for gh pr list / gh issue list via the CLI proxy.

Disables strict mode in these three workflows to allow the
sandbox.mcp.version field (internal implementation detail).

Tracking issue: github/gh-aw-mcpg#4276

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Author: lpcox

.github/workflows/smoke-claude.lock.yml

@@ -19,7 +19,10 @@ engine:
   max-turns: 12
 features:
   cli-proxy: true
-strict: true
+sandbox:
+  mcp:
+    version: v0.2.29
+strict: false
 network:
   allowed:
     - defaults