feat(tester): support isolated full regression workflow

skills/test-preflight/references/schema.md

@@ -18,6 +18,10 @@ fixtures:
 cleanup:
   required: true
   steps: [delete-run-data]
+capabilities:
+  # These baseline checks are mandatory for mobile rows and cannot be disabled
+  # with AUTHORIZE_ALBUM or IME_PINYIN.
+  required: [album_picker, photo_permission, ime_pinyin]
 matrix:
   - platform: android
     tester:
@@ -48,6 +52,35 @@ needs non-empty `references`; a required cleanup needs non-empty `steps` or
 `run`. For a read-only run, use `required: false` with a non-empty `reason`.
 The skill never executes these values.
 
+## Mobile capability contract
+
+Every Android/iOS matrix row checks these capabilities on the actual tester node:
+
+| capability | required evidence |
+|---|---|
+| `album_picker` | `checks.picker`: the real platform album/Photos picker opened and returned a selectable asset |
+| `photo_permission` | `checks.permission` and `checks.test_image`: permission state was exercised and the declared test image was available |
+| `ime_pinyin` | `checks.composition` and `checks.candidates`: real Chinese pinyin composition and candidate selection succeeded |
+
+The default list is always applied; `capabilities.required` can add project-specific
+checks but cannot remove these three. A contract runner receives one request per
+capability:
+
+```json
+{
+  "operation": "capability_probe",
+  "platform": "android",
+  "node": "tester.android",
+  "capability": "ime_pinyin",
+  "required_checks": ["composition", "candidates"]
+}
+```
+
+It must return every requested check with `status`, `observed`, and (when useful)
+`expected`/`remediation`. Missing evidence is `blocked`; a real probe failure is
+`environment-fail`. Environment variables such as `AUTHORIZE_ALBUM` and
+`IME_PINYIN` are not capability evidence.
+
 ## Tester-node contract
 
 `tester.runner.kind: local` executes platform and network probes on the current