Deploy multi-file Hub workflows (#3128)

* feat(hub): deploy canonical workflow bundles

Keep CLI deployment aligned with Hub's authored bundle boundary so validation and activation receive the same deterministic source files. Public documentation now teaches that boundary as the only configuration format.

* test(hub): assert validation diagnostics directly

* refactor(hub): deepen HTTP client module

* feat(hub): validate named agent configurations

* docs(hub): align Claude mode example

public-docs/hub/self-hosting/github-app.md

@@ -29,7 +29,7 @@ Repository permissions:
 
 | Permission    | Access       | Why                                       |
 | ------------- | ------------ | ----------------------------------------- |
-| Contents      | Read & write | Read `.paseo/hub.yml`, let agents push    |
+| Contents      | Read & write | Read the `.paseo` bundle, let agents push |
 | Issues        | Read & write | Read comments, add reactions              |
 | Pull requests | Read & write | Read review comments, let agents open PRs |
 | Metadata      | Read         | Required by GitHub                        |
@@ -42,7 +42,7 @@ Subscribe to events:
 - Pull request review comment
 - Push
 
-Push is what makes configuration sync work. Without it, Hub never learns that `.paseo/hub.yml` changed.
+Push is what makes configuration sync work. Without it, Hub never learns that the `.paseo` bundle changed.
 
 ## Configure Hub
 
@@ -74,7 +74,7 @@ Connect as many installations as you need. A personal account and several organi
 ## What the connection gives you
 
 - **Events.** Comments, issues, and reviews from every repository the installation can see. See [GitHub triggers](/docs/hub/triggers/github).
-- **Configuration sync.** Any repository in the installation can hold `.paseo/hub.yml`. See [Configuration](/docs/hub/configuration).
+- **Configuration sync.** Any repository in the installation can hold the canonical `.paseo` bundle. See [Configuration](/docs/hub/configuration).
 - **Tokens.** Scoped, per-execution GitHub credentials.
 
 Which repositories the installation covers is a GitHub setting. Change it on GitHub, not in Paseo.