Extract slideshow into a plugin (blueprint-only display plugin)

Second core feature pulled into a plugin. Slides is the minimal plugin shape:
a blueprint only - no model, no AssetType, no nav (it is purely an API surface
consumed by the TV dashboard).

- plugins/slides/: manifest (api_prefix /api/slides, no deps), api/ (moved
  blueprint, contract-pure imports via shopdb.api, same /api/slides route so the
  TV dashboard is unchanged), plugin.py (get_blueprint, get_models -> []).
- Fixed a latent bug in the move: error path used ErrorCodes.SERVER_ERROR which
  does not exist -> ErrorCodes.INTERNAL_ERROR.
- De-cored: deleted shopdb/core/api/slides.py, removed from CORE_BLUEPRINT_NAMES
  + core/api/__init__ import/__all__. Registered in instance/plugins.json.

Pinned with a characterization test first; passes unchanged against the plugin
blueprint. 174 tests pass, naming green, app boots 8 bundled plugins, /api/slides
verified live.

Note: the shopfloor dashboard is NOT extractable - it is a frontend-only Vue view
aggregating the businessunits + notifications APIs, with no backend to move and no
frontend plugin system.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

shopdb/__init__.py

@@ -106,7 +106,6 @@ CORE_BLUEPRINT_NAMES = (
     'reports',
     'collector',
     'employees',
-    'slides',
     'settings',
     'auditlogs',
     'users',

shopdb/core/api/__init__.py

@@ -15,7 +15,6 @@ from .search import search_bp
 from .reports import reports_bp
 from .collector import collector_bp
 from .employees import employees_bp
-from .slides import slides_bp
 from .settings import settings_bp
 from .auditlogs import auditlogs_bp
 from .users import users_bp
@@ -36,7 +35,6 @@ __all__ = [
     'reports_bp',
     'collector_bp',
     'employees_bp',
-    'slides_bp',
     'settings_bp',
     'auditlogs_bp',
     'users_bp',

shopdb/core/api/slides.py

@@ -1,74 +0,0 @@
-"""Slides API for TV dashboard slideshow."""
-
-import os
-from flask import Blueprint, current_app
-from shopdb.utils.responses import success_response, error_response, ErrorCodes
-
-slides_bp = Blueprint('slides', __name__)
-
-# Valid image extensions
-VALID_EXTENSIONS = {'.jpg', '.jpeg', '.png', '.gif', '.bmp', '.webp'}
-
-
-@slides_bp.route('', methods=['GET'])
-def get_slides():
-    """
-    Get list of slides for TV dashboard.
-
-    Returns image files from the static/slides directory.
-    """
-    # Look for slides in static folder
-    static_folder = current_app.static_folder
-    if not static_folder:
-        static_folder = os.path.join(current_app.root_path, 'static')
-
-    slides_folder = os.path.join(static_folder, 'slides')
-
-    # Also check frontend public folder
-    frontend_slides = os.path.join(
-        os.path.dirname(os.path.dirname(os.path.dirname(current_app.root_path))),
-        'frontend', 'public', 'slides'
-    )
-
-    # Try multiple possible locations
-    possible_paths = [
-        slides_folder,
-        frontend_slides,
-        '/home/camp/projects/shopdb-flask/shopdb/static/slides',
-        '/home/camp/projects/shopdb-flask/frontend/public/slides',
-    ]
-
-    slides_path = None
-    for path in possible_paths:
-        if os.path.isdir(path):
-            slides_path = path
-            break
-
-    if not slides_path:
-        return success_response({
-            'slides': [],
-            'basepath': '/static/slides/',
-            'message': 'Slides folder not found'
-        })
-
-    # Get list of image files
-    slides = []
-    try:
-        for filename in sorted(os.listdir(slides_path)):
-            ext = os.path.splitext(filename)[1].lower()
-            if ext in VALID_EXTENSIONS:
-                slides.append({'filename': filename})
-    except Exception as e:
-        return error_response(
-            ErrorCodes.SERVER_ERROR,
-            f'Error reading slides: {str(e)}',
-            http_code=500
-        )
-
-    # Determine base path for serving files
-    basepath = '/static/slides/'
-
-    return success_response({
-        'slides': slides,
-        'basepath': basepath
-    })