feat: modernize build tooling and add CI/CD workflow

Switch to Bun for 2-5x faster frontend builds, implement cargo-chef for
reliable Rust dependency caching, and add Biome for fast code
formatting.

Build system improvements:
- Replace pnpm with Bun for frontend package management
- Add cargo-chef to Dockerfile for better Rust build layer caching
- Update all commands to use bun instead of pnpm

Developer experience:
- Add comprehensive Justfile commands (format, format-check, db)
- Implement automated PostgreSQL Docker setup with random port
allocation
- Add stricter checks (--deny warnings on clippy, --all-features flag)

Code quality:
- Add Biome formatter for 10-100x faster TypeScript/JavaScript
formatting
- Add GitHub Actions CI/CD workflow for automated checks
- Update .dockerignore with comprehensive exclusions
- Format all code with cargo fmt (Rust) and Biome (TypeScript)

All changes maintain backward compatibility and can be tested
incrementally.

web/src/lib/api.ts

@@ -38,9 +38,7 @@ export class BannerApiClient {
     const response = await fetch(`${this.baseUrl}${endpoint}`);
 
     if (!response.ok) {
-      throw new Error(
-        `API request failed: ${response.status} ${response.statusText}`
-      );
+      throw new Error(`API request failed: ${response.status} ${response.statusText}`);
     }
 
     return (await response.json()) as T;