chore: bump version to v0.30.1

Update version across all packages:
- Go CLI (cmd/bd/version.go)
- Python MCP server (pyproject.toml, __init__.py)
- npm package (package.json)

Add comprehensive CHANGELOG entry with 14 features, 14 fixes,
security updates, and community contributor credits.

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

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

cmd/bd/version.go

@@ -14,7 +14,7 @@ import (
 
 var (
 	// Version is the current version of bd (overridden by ldflags at build time)
-	Version = "0.30.0"
+	Version = "0.30.1"
 	// Build can be set via ldflags at compile time
 	Build = "dev"
 	// Commit and branch the git revision the binary was built from (optional ldflag)