Redesign SpoolBuddy dashboard: inline spool cards, full-screen AMS assign modal, filament ID normalization

- Replace TagDetectedModal with inline SpoolInfoCard/UnknownTagCard
    in dashboard right panel (known spools show assign/sync/close,
    unknown tags show add-to-inventory/link/close)
  - Rewrite AssignToAmsModal as full-screen overlay reusing AmsUnitCard,
    with AMS-HT and external slot support, single assignSpool API call
  - Remove printer selector from assign modal (uses top bar selection)
  - Extract filament_id <-> setting_id conversion to shared utility
    (backend/app/utils/filament_ids.py), used by inventory + cloud routes
  - Normalize slicer_filament in assign_spool to derive proper
    tray_info_idx and setting_id for MQTT (was sending setting_id="")
  - Rename SpoolBuddy top bar status label "Online" -> "Backend"
  - Remove weightStable guard from sync weight button

backend/app/api/routes/cloud.py

@@ -38,6 +38,7 @@ from backend.app.services.bambu_cloud import (
     BambuCloudError,
     get_cloud_service,
 )
+from backend.app.utils.filament_ids import filament_id_to_setting_id
 
 logger = logging.getLogger(__name__)
 
@@ -503,32 +504,8 @@ async def _enrich_from_local_presets(
     return result
 
 
-def _filament_id_to_setting_id(filament_id: str) -> str:
-    """
-    Convert filament_id to setting_id format for Bambu Cloud API.
-
-    Printers report filament_id (e.g., GFA00, GFG02) but the API expects
-    setting_id format which has an "S" inserted after "GF" (e.g., GFSA00, GFSG02).
-
-    User presets (starting with "P") and already-correct IDs are returned unchanged.
-    """
-    if not filament_id:
-        return filament_id
-
-    # User presets start with "P" - leave unchanged
-    if filament_id.startswith("P"):
-        return filament_id
-
-    # Official Bambu presets: GFx## -> GFSx##
-    # Check if it matches the filament_id pattern (GF followed by letter and digits)
-    if filament_id.startswith("GF") and len(filament_id) >= 4:
-        # Check if it's already a setting_id (has S after GF)
-        if filament_id[2] == "S":
-            return filament_id
-        # Insert "S" after "GF": GFA00 -> GFSA00
-        return f"GFS{filament_id[2:]}"
-
-    return filament_id
+# _filament_id_to_setting_id is now imported from backend.app.utils.filament_ids
+_filament_id_to_setting_id = filament_id_to_setting_id
 
 
 @router.post("/filament-info")

backend/app/api/routes/inventory.py

@@ -30,6 +30,7 @@ from backend.app.schemas.spool import (
     SpoolUpdate,
 )
 from backend.app.schemas.spool_usage import SpoolUsageHistoryResponse
+from backend.app.utils.filament_ids import normalize_slicer_filament
 
 logger = logging.getLogger(__name__)
 
@@ -733,8 +734,7 @@ async def assign_spool(
             tray_type = spool.material
             tray_sub_brands = f"{spool.material} {spool.subtype}" if spool.subtype else spool.material
             tray_color = spool.rgba or "FFFFFFFF"
-            tray_info_idx = spool.slicer_filament or ""
-            setting_id = ""
+            tray_info_idx, setting_id = normalize_slicer_filament(spool.slicer_filament)
 
             # Resolve tray_info_idx for the MQTT command.
             # Priority: