Repair settings: dropdown for fixed-choice settings (canonical source_selection)

The canonical source_selection setting was rendering as a free-text box — easy
to typo an invalid mode. Added a generic choice mechanism so it's a dropdown:

- RepairJob.setting_options: {key: [allowed values]} (default {} — opt-in).
- CanonicalVersionResolveJob declares source_selection's three modes.
- repair_worker.get_all_job_info() includes setting_options in the job payload.
- enrichment.js renders a <select> (options prettified, current value selected)
  for any key listed in setting_options; everything else renders by value type
  as before. The save path already reads <select>.value as a string, so no
  change needed there.

Generic — any future job can get dropdowns the same way. Jobs that don't
declare setting_options are untouched (empty dict -> existing input rendering).

Tests: source_selection exposes the 3 options and its default is one of them.
23 repair-job/worker + canonical tests pass (other jobs unaffected).

core/repair_jobs/base.py

@@ -100,6 +100,9 @@ class RepairJob(ABC):
     default_enabled: bool = False
     default_interval_hours: int = 24
     default_settings: Dict[str, Any] = {}
+    # Optional {setting_key: [allowed values]} — the UI renders a dropdown for
+    # these instead of a free-text box. Keys not listed render by value type.
+    setting_options: Dict[str, list] = {}
     auto_fix: bool = False
 
     @abstractmethod

core/repair_jobs/canonical_version_resolve.py

@@ -101,6 +101,10 @@ class CanonicalVersionResolveJob(RepairJob):
         # source matches the files best, regardless of which it is).
         'source_selection': 'active_preferred',
     }
+    # Render source_selection as a dropdown (not a text box) in the settings UI.
+    setting_options = {
+        'source_selection': ['active_preferred', 'active_only', 'best_fit'],
+    }
     auto_fix = True
 
     def _get_settings(self, context: JobContext) -> dict:

core/repair_worker.py

@@ -371,6 +371,9 @@ class RepairWorker:
                 'interval_hours': config['interval_hours'],
                 'settings': config['settings'],
                 'default_settings': job.default_settings.copy(),
+                # Per-setting choice lists so the UI can render a dropdown
+                # instead of a free-text box (e.g. canonical source_selection).
+                'setting_options': dict(getattr(job, 'setting_options', {}) or {}),
                 'last_run': last_run,
                 'next_run': next_run,
                 'is_running': self._current_job_id == job_id,

tests/test_canonical_version_job.py

@@ -59,6 +59,14 @@ def test_source_selection_defaults_to_active_preferred():
     assert CanonicalVersionResolveJob.default_settings["source_selection"] == "active_preferred"
 
 
+def test_source_selection_exposes_dropdown_options():
+    # The UI renders a <select> for keys listed in setting_options.
+    opts = CanonicalVersionResolveJob.setting_options.get("source_selection")
+    assert opts == ["active_preferred", "active_only", "best_fit"]
+    # default must be one of the offered options
+    assert CanonicalVersionResolveJob.default_settings["source_selection"] in opts
+
+
 def test_describe_pin_is_judgeable():
     desc = _describe_pin({
         "source": "deezer", "album_id": "665666731", "score": 1.0,

webui/static/enrichment.js

@@ -1705,6 +1705,18 @@ async function loadRepairJobs() {
                         return `<div class="repair-setting-section">${val}</div>`;
                     }
                     const label = _prettifyRepairSettingKey(key);
+                    // Dropdown when the job declares allowed values for this key.
+                    const opts = job.setting_options && job.setting_options[key];
+                    if (Array.isArray(opts) && opts.length) {
+                        const optionsHtml = opts.map(o =>
+                            `<option value="${o}"${o === val ? ' selected' : ''}>${_prettifyRepairSettingKey(String(o))}</option>`
+                        ).join('');
+                        return `<div class="repair-setting-row">
+                            <label>${label}</label>
+                            <select class="repair-setting-input"
+                                    data-job="${job.job_id}" data-key="${key}">${optionsHtml}</select>
+                        </div>`;
+                    }
                     const inputType = typeof val === 'boolean' ? 'checkbox' :
                         typeof val === 'number' ? 'number' : 'text';
                     const inputVal = inputType === 'checkbox' ?