printedparts stage 15: print-file revision history + role-based alerts

printeditemfiles lands as the plugin's first incremental migration
(0002 on the plugin chain - the ADR-008 payoff). Revisions are
append-only per item: upload assigns the next number, records the
uploader from the JWT, enforces an extension allowlist and a 100 MB
cap; download serves the original filename; a permission-gated delete
covers wrong-file mistakes. The detail page gains the revision table
with a current badge. Unique storedfilename is sized 191 so the index
fits MySQL's 767-byte prefix - the per-plugin chain does not apply the
core env's ROW_FORMAT hook.

Alert recipients gain roles: Role joins the 0.13.0 surface, a role
picker on the settings page, and every active member of the selected
roles is folded into the deduped recipient list.

plugins/printedparts/api/routes.py

@@ -268,7 +268,7 @@ def _alert_recipients():
     """Merge selected shopdb users' account emails with the free-text list.
 
     Empty result means fall back to the site-wide alert_recipients."""
-    from shopdb.api import User
+    from shopdb.api import User, Role
     recipients = []
     userids = (Setting.get('printedparts_alert_userids') or '').strip()
     for rawid in userids.split(','):
@@ -278,6 +278,15 @@ def _alert_recipients():
         user = db.session.get(User, int(rawid))
         if user and user.isactive and user.email:
             recipients.append(user.email)
+    roleids = (Setting.get('printedparts_alert_roleids') or '').strip()
+    for rawid in roleids.split(','):
+        rawid = rawid.strip()
+        if not rawid.isdigit():
+            continue
+        role = db.session.get(Role, int(rawid))
+        if role:
+            recipients.extend(member.email for member in role.users
+                              if member.isactive and member.email)
     extra = (Setting.get('printedparts_alert_email') or '').strip()
     recipients.extend(address.strip() for address in extra.split(',')
                       if address.strip())
@@ -525,3 +534,126 @@ def report_by_person():
     if request.args.get('format') == 'csv':
         return _csv_response(rows, columns, 'printedparts-by-person.csv')
     return success_response({'columns': columns, 'rows': rows, 'days': days})
+
+
+# --- print files: append-only revisions per item ------------------------------
+
+from flask_jwt_extended import get_jwt_identity
+
+from ..models import PrintedItemFile
+
+FILE_EXTENSIONS = {'.stl', '.3mf', '.gcode', '.gco', '.bgcode', '.step',
+                   '.stp', '.obj', '.amf'}
+MAX_FILE_BYTES = 100 * 1024 * 1024
+
+
+def _filedir():
+    return os.path.join(current_app.instance_path, 'printedpartsfiles')
+
+
+def _uploader_name():
+    from shopdb.api import User
+    identity = get_jwt_identity()
+    try:
+        user = db.session.get(User, int(identity))
+        if user:
+            return user.username
+    except (TypeError, ValueError):
+        pass
+    return str(identity)
+
+
+@printedparts_bp.route('/items/<int:item_id>/files', methods=['GET'])
+@jwt_required(optional=True)
+def list_item_files(item_id: int):
+    """Revision history, newest first."""
+    files = (PrintedItemFile.query.filter_by(printeditemid=item_id)
+             .order_by(PrintedItemFile.revision.desc()).all())
+    return success_response([f.to_dict() for f in files])
+
+
+@printedparts_bp.route('/items/<int:item_id>/files', methods=['POST'])
+@jwt_required()
+@require_permission('printedparts.edit')
+def upload_item_file(item_id: int):
+    """Upload the next revision of the item's print file.
+
+    multipart/form-data: file=<stl/3mf/gcode/...>, note=<what changed>.
+    Revisions are append-only; nothing is replaced.
+    """
+    item = db.session.get(PrintedItem, item_id)
+    if not item:
+        return error_response(ErrorCodes.NOT_FOUND,
+                              f'Printed item {item_id} not found', http_code=404)
+    upload = request.files.get('file')
+    if not upload or not upload.filename:
+        return error_response(ErrorCodes.VALIDATION_ERROR, 'No file provided')
+    ext = os.path.splitext(upload.filename)[1].lower()
+    if ext not in FILE_EXTENSIONS:
+        return error_response(
+            ErrorCodes.VALIDATION_ERROR,
+            f'Unsupported file type {ext}; allowed: '
+            + ', '.join(sorted(FILE_EXTENSIONS)))
+
+    upload.stream.seek(0, os.SEEK_END)
+    filesize = upload.stream.tell()
+    upload.stream.seek(0)
+    if filesize > MAX_FILE_BYTES:
+        return error_response(ErrorCodes.VALIDATION_ERROR,
+                              'File exceeds the 100 MB limit')
+
+    latest = (db.session.query(db.func.max(PrintedItemFile.revision))
+              .filter_by(printeditemid=item_id).scalar()) or 0
+    revision = latest + 1
+
+    filedir = _filedir()
+    os.makedirs(filedir, exist_ok=True)
+    storedfilename = secure_filename(
+        f'printeditem-{item_id}-rev{revision}{ext}')
+    upload.save(os.path.join(filedir, storedfilename))
+
+    record = PrintedItemFile(
+        printeditemid=item_id,
+        revision=revision,
+        filename=secure_filename(upload.filename),
+        storedfilename=storedfilename,
+        filesize=filesize,
+        uploadnote=(request.form.get('note') or '').strip() or None,
+        uploadedby=_uploader_name(),
+    )
+    db.session.add(record)
+    db.session.commit()
+    return success_response(record.to_dict(),
+                            message=f'Revision {revision} uploaded',
+                            http_code=201)
+
+
+@printedparts_bp.route('/files/<int:file_id>/download', methods=['GET'])
+@jwt_required(optional=True)
+def download_item_file(file_id: int):
+    """Download a revision under its original filename."""
+    from flask import send_from_directory
+    record = db.session.get(PrintedItemFile, file_id)
+    if not record:
+        return error_response(ErrorCodes.NOT_FOUND, 'File not found',
+                              http_code=404)
+    return send_from_directory(_filedir(), record.storedfilename,
+                               as_attachment=True,
+                               download_name=record.filename)
+
+
+@printedparts_bp.route('/files/<int:file_id>', methods=['DELETE'])
+@jwt_required()
+@require_permission('printedparts.delete')
+def delete_item_file(file_id: int):
+    """Remove a bad revision (wrong file uploaded). History otherwise stays."""
+    record = db.session.get(PrintedItemFile, file_id)
+    if not record:
+        return error_response(ErrorCodes.NOT_FOUND, 'File not found',
+                              http_code=404)
+    path = os.path.join(_filedir(), record.storedfilename)
+    if os.path.exists(path):
+        os.remove(path)
+    db.session.delete(record)
+    db.session.commit()
+    return success_response(message='Revision removed')