Local deployment template requires ADC and Cloud Logging at import time

生成一个 deployment_target: none 的 ADK 项目，然后检查 app/fast_api_app.py，并在没有 Application Default Credentials 的隔离环境中导入它。跟踪 --otel-to-cloud 入口点和子环境处理逻辑，然后运行报告的回归测试套件；完成的标准是本地启动不需要 ADC 或 Cloud Logging，同时精确的 opt-in 传播和现有的 fallback 行为仍得到覆盖。

Baseline

Reproduced from v1.3.1 at 5a306f8956cb1eeae69f9709de0e4d61b44e11e7.

Reproduction

1. Generate an ADK project with deployment_target: none.
2. Use an isolated local environment without Application Default Credentials.
3. Import or start the generated app/fast_api_app.py.

The generated module unconditionally calls google.auth.default(), constructs google.cloud.logging.Client(), and always sets otel_to_cloud=True.

Actual behavior

A local-only template needs cloud credentials and a Cloud Logging dependency merely to import/start. This makes the none target fail in a normal offline/no-ADC development environment.

Expected behavior

The local target should use Python stdlib logging and start without ADC. Existing cloud OTEL behavior should remain opt-in through the public --otel-to-cloud flag only.

Minimal fix

• use logging.getLogger(__name__) in the local template and remove its Cloud Logging dependency;
• pass a private child-only AGENTS_CLI_OTEL_TO_CLOUD=1 value only when --otel-to-cloud is explicitly set;
• remove any inherited copy of that private variable when the option is off;
• read the private flag before loading project .env files, accepting only the exact value 1.

Reference implementation: https://github.com/benagentai93-dot/agents-cli/commit/d888f8db85d05e7bb4ed92c711045a246c00b537

Test evidence

Runnable regressions cover dependency output, import without ADC, exact opt-in behavior, inherited-environment removal, explicit child propagation, and the existing ADK fallback flag.

Fork verification on Python 3.11/3.13:

• focused Batch 1 suite: 17 passed
• full root suite: 19 passed
• lint, type check, build, and installed-wheel smoke: passed