Add the managed plugin daemon API

[Aaronontheweb]

Netclaw needs daemon ownership for plugin configuration and explicit retries.

This change adds authenticated /api/plugins routes.

The API preserves unrelated configuration and rejects invalid values before persistence.

It returns the stable source ID and current manifest name as separate fields.

The shared sync actor supports an explicit retry pass for rejected commits.

Validation:

• This branch builds against the preceding PR.
• The full stack passed 8,588 tests and skipped 23 environment-specific tests.
• Slopwatch found no issues.
• The file-header and diff checks passed.

Depends on #2162.
Part of #2134.

Pull request stack

Review and merge these pull requests in this order:

1. Adopt plugin-neutral source and state contracts #2160: Adopt plugin-neutral source and state contracts.
2. Add Agent Plugins and Codex package adapters #2161: Add Agent Plugins and Codex package adapters.
3. Publish managed plugins during external sync #2162: Publish managed plugins during external sync.
4. Add the managed plugin daemon API #2157: Add the managed plugin daemon API.
5. Add the managed plugin CLI #2158: Add the managed plugin CLI.

This pull request is step 4.

[Aaronontheweb]

Adversarial review complete.

I checked authorization, canonical configuration persistence, reference resolution, restart generation, and retry actor behavior.

I found no concrete defect in this slice. The focused API tests pass.

[Aaronontheweb]

I found no defect that is specific to this slice. The daemon correctly owns authorization, reference resolution, config writes, and installed-state reads. The CLI discards the API safe problem details. I reported that consumer defect on #2158.

[Aaronontheweb]

The API ownership is correct. The daemon owns validation, reference resolution, configuration writes, and installed-state reads.

One required error-disclosure correction remains in the inline thread.

I reviewed commit b52a67e. Local checks passed with 8,588 tests, strict OpenSpec validation, Slopwatch, headers, and diff checks.

Local evals lacked provider credentials. Chromium lacked a usable sandbox for native tapes. GitHub checks are still active.

[Aaronontheweb]

[P2] Do not publish internal exception messages as safe problem details.

GitSkillPluginConfigStore includes IOException and UnauthorizedAccessException messages. Those messages can contain the absolute configuration path.

This line returns that text to every authenticated API client. It also accepts unbounded text from other expected exception types.

Map each failure to a bounded public detail. Log the original exception on the daemon. Add a path-disclosure regression test.

[Aaronontheweb]

Fixed at e8e90f7. Config read, parse, and write errors now return bounded public text. The route logs the exception with its inner cause. An endpoint test proves the config path stays out of the response.