[information-architecture] Scheduled Audit manual trigger hides required configuration inputs

## Information Architecture Findings

### 1. `workflow_dispatch` entry point does not expose the controls documented as required
**Area:** Action placement / Progressive disclosure
**Component(s):** `gh-agent-workflows/scheduled-audit/README.md`, `gh-agent-workflows/scheduled-audit/example.yml`

**Problem:**
The docs present `workflow_dispatch` as a manual entry point and document key inputs (`additional-instructions`, `title-prefix`) as required configuration. But the manual trigger in `example.yml` defines no `workflow_dispatch.inputs`, so users launching from the Actions UI cannot set those controls at run time.

That creates a confusing IA mismatch: the primary manual entry point lacks the controls users are told to provide.

**Evidence:**
- `gh-agent-workflows/scheduled-audit/README.md:30` lists `workflow_dispatch` as `Manual`.
- `gh-agent-workflows/scheduled-audit/README.md:36-37` marks `additional-instructions` and `title-prefix` as required.
- `gh-agent-workflows/scheduled-audit/example.yml:5` has `workflow_dispatch:` with no `inputs` block.
- Contrast pattern: `gh-agent-workflows/pr-actions-fixer/example.yml:3-8` exposes required manual input(s) under `workflow_dispatch.inputs`.

**Suggested improvement:**
Add `workflow_dispatch.inputs` for the key manual-run controls (at least `additional-instructions`, plus other relevant knobs such as `title-prefix`, `close-older-issues`, `issue-label`, `setup-commands`), and wire those inputs in `jobs.run.with` for manual runs. This aligns the manual UI with the documented configuration model.

## Suggested Actions
- [ ] Add `workflow_dispatch.inputs` to `gh-agent-workflows/scheduled-audit/example.yml` for manual-run configuration fields.
- [ ] Reference `$\{\{ inputs.* }}` values in `jobs.run.with` for manual runs, with sensible defaults where appropriate.
- [ ] Keep `README.md` input requirements synchronized with what is actually exposed in the manual trigger UI.

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