## Why
Recent merges left `main` with analytics integration build failures.
Local Cargo runs also made the trimmed-skills test depend on
developer-installed skills, while Bazel used an isolated home.
## What changed
- Clone `thread_metadata.thread_source` when constructing goal analytics
event parameters.
- Group app-server thread extension inputs into
`ThreadExtensionDependencies`.
- Isolate the trimmed-skills test home so its exact fixture count is
stable across Cargo and Bazel.
## Validation
- `cargo check -p codex-analytics`
- `just test -p codex-analytics` (71 tests)
- `just test -p codex-app-server` (837 tests; one unrelated zsh-fork
timeout passed on retry)
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