Remove brand functionality and update Bambu Lab colors

- Remove brand field from entire codebase (frontend, backend, database)
- Update Bambu Lab colors to official list with correct hex values
- Clean up unused code and type definitions
- Add database migration to drop brand column
- Update search and filters to exclude brand references
- Ensure data persistence across all application layers

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: DaX <noreply@anthropic.com>

database/schema.sql

@@ -15,7 +15,6 @@ CREATE TABLE colors (
 -- Filaments table
 CREATE TABLE filaments (
   id UUID PRIMARY KEY DEFAULT uuid_generate_v4(),
-  brand VARCHAR(100) NOT NULL,
   tip VARCHAR(50) NOT NULL,
   finish VARCHAR(50) NOT NULL,
   boja VARCHAR(100) NOT NULL,
@@ -31,7 +30,6 @@ CREATE TABLE filaments (
 );
 
 -- Create indexes for better performance
-CREATE INDEX idx_filaments_brand ON filaments(brand);
 CREATE INDEX idx_filaments_tip ON filaments(tip);
 CREATE INDEX idx_filaments_boja ON filaments(boja);
 CREATE INDEX idx_filaments_created_at ON filaments(created_at);