feat(cropper): save with the session token — no OTP, domain from a2loft

Consumes the a2loft cropper-token-auth change: the save now sends the
session's PocketBase token as a bearer credential and no phone/otp. The
backend authorizes with OpenFGA crop_image (domain:<code> -> domain:idid),
so an operator no longer needs super-user rights in the profile's domain —
which is what made saves fail with a blanket 'Invalid OTP specified.'.

- the save's domain comes from a2loft's own record of the picture
  (dims/picture/{uploadId} -> domainCode), falling back to the queue label,
  guarded by a path-safety pattern instead of the catalog check
- the 'core' -> 'uc' alias is deleted: 'core' is a2loft's own pseudo-domain
  for a profile picture (special-cased there), so rewriting it changed the
  attribution and the ID-card notification
- queue loads are enriched with the profile's domainCode; the panel shows
  the profile's domain and, when it differs, the picture target
- the cropper's OTP field, state and parameters are gone; the fingerprint
  wizard is untouched (its own OTP flow on its own endpoints)
- tests updated: bearer + no query auth, resolved domain wins, unsafe values
  refused, no OTP field served (46 pass)

Requires the a2loft change deployed first.

openspec/changes/cropper-token-auth/specs/image-cropper/spec.md

@@ -0,0 +1,37 @@
+# Spec Delta: image-cropper
+
+## MODIFIED Requirements
+
+### Requirement: Saving requires a live gate and an OTP
+Saving a cropped picture (`/cropper/profile/picture`) SHALL verify the crop
+permission live (bypassing the cache) and SHALL authenticate the operator with
+the session's PocketBase token, sent to a2loft as a bearer credential; no OTP
+SHALL be collected or forwarded. The picture's domain SHALL come from a2loft's
+own record for the upload (`dims/picture/{uploadId}` → `domainCode`), falling
+back to the queue item's label, and SHALL match a path-safe pattern before it
+is used in the request. A denied save SHALL not reach a2loft.
+
+#### Scenario: Successful save
+- **WHEN** a permitted operator saves
+- **THEN** the route verifies the live gate and forwards the picture to
+  a2loft with the session token as a bearer credential and the profile's
+  resolved domain
+
+#### Scenario: Denied save does not reach a2loft
+- **WHEN** the live crop check denies, or the request carries no message body
+- **THEN** the route answers 403/400 and makes no a2loft call
+
+#### Scenario: Unsafe domain values are refused
+- **WHEN** neither a2loft's record nor the queue label yields a path-safe
+  domain
+- **THEN** the save is refused with 400 and a2loft is not contacted
+
+### Requirement: Unified login — no separate artist login
+The cropper SHALL NOT implement its own login. The operator's identity comes
+from the YOUreka session and is presented to a2loft as the session's PocketBase
+token; the picture's own metadata carries the domain. The cropper collects no
+other credential — there is no save-time OTP.
+
+#### Scenario: Phone prefilled from the session
+- **WHEN** a signed-in operator opens the cropper
+- **THEN** their phone is already known to the page without any login form