fix: resolve 25 pre-publish blockers

- postinstall.mjs: fix alias package detection
- migrate-legacy-plugin-entry: dedupe + regression tests
- task_system: default consistency across runtime paths
- task() contract: consistent tool behavior
- runtime model selection, tool cap, stale-task cancellation
- recovery sanitization, context-limit gating
- Ralph semantic DONE hardening, Atlas fallback persistence
- native-skill description/content, skill path traversal guard
- publish workflow: platform awaited via reusable workflow job
- release: version edits reapplied before commit/tag
- JSONC plugin migration: top-level plugin key safety
- cold-cache: user fallback models skip disconnected providers
- docs/version/release framing updates

Verified: bun test (4599 pass), tsc --noEmit clean, bun run build clean

src/plugin-handlers/agent-config-handler.ts

@@ -90,7 +90,7 @@ export async function applyAgentConfig(params: {
     params.pluginConfig.browser_automation_engine?.provider ?? "playwright";
   const currentModel = params.config.model as string | undefined;
   const disabledSkills = new Set<string>(params.pluginConfig.disabled_skills ?? []);
-  const useTaskSystem = params.pluginConfig.experimental?.task_system ?? false;
+  const useTaskSystem = params.pluginConfig.experimental?.task_system ?? true;
   const disableOmoEnv = params.pluginConfig.experimental?.disable_omo_env ?? false;
 
   const includeClaudeAgents = params.pluginConfig.claude_code?.agents ?? true;