fix: launch scheduled tasks with the sdk cli entrypoint

Scheduled task subprocesses should normalize their child environment instead of inheriting a stale parent entrypoint. Setting the default task entrypoint keeps launcher tests and non-OAuth task execution on the SDK CLI path while still allowing the official OAuth environment overlay to provide its desktop-specific entrypoint.

Constraint: Official OAuth tasks intentionally overlay provider-specific environment after the default child task environment is built
Rejected: Preserve parent CLAUDE_CODE_ENTRYPOINT | stale parent values can leak into scheduled task launches
Confidence: high
Scope-risk: narrow
Directive: Keep default task launcher environment deterministic before provider-specific overlays are applied
Tested: bun test src/server/__tests__/cron-scheduler-launcher.test.ts
Tested: bun run check:server
Not-tested: Full verify still blocked by existing agent-utils global coverage baseline

src/server/__tests__/cron-scheduler-launcher.test.ts

@@ -244,6 +244,7 @@ describe('cron scheduler launcher resolution', () => {
     process.env.CLAUDE_APP_ROOT = appRoot
     process.env.ANTHROPIC_BASE_URL = 'https://stale-parent.example'
     process.env.ANTHROPIC_MODEL = 'stale-parent-model'
+    process.env.CLAUDE_CODE_ENTRYPOINT = 'stale-parent-entrypoint'
 
     const provider = await new ProviderService().addProvider({
       presetId: 'custom',

src/server/services/cronScheduler.ts

@@ -662,6 +662,7 @@ export class CronScheduler {
     return {
       ...cleanEnv,
       CLAUDE_CODE_ENABLE_TASKS: '1',
+      CLAUDE_CODE_ENTRYPOINT: 'sdk-cli',
       CALLER_DIR: workDir,
       PWD: workDir,
       CC_HAHA_SKIP_DOTENV: '1',