chore(release): bump version to 4.2.0

The next release adds public exports for the prompt-async-gate primitives
(promptAsyncAfterSessionIdle, promptAfterSessionIdle,
releasePromptAsyncReservation, DEFAULT_PROMPT_ASYNC_POST_DISPATCH_HOLD_MS)
and introduces new safety semantics that affect 13+ internal hook callers.
Per semver, adding public exports mandates a MINOR bump from 4.1.x.
No public API removals or breaking signature changes, so this is NOT MAJOR.

Closes pre-publish-review version-bump consensus

Co-authored-by: api-surface (deep / gpt-5.3-codex high)

package.json

@@ -1,6 +1,6 @@
 {
   "name": "oh-my-opencode",
-  "version": "4.1.2",
+  "version": "4.2.0",
   "description": "The Best AI Agent Harness - Batteries-Included OpenCode Plugin with Multi-Model Orchestration, Parallel Background Agents, and Crafted LSP/AST Tools",
   "main": "./dist/index.js",
   "types": "dist/index.d.ts",