feat: lifetime elision, tooling CI, registry, and LSP locals

Ship the QUALITY_PLAN stretch from ownership through ecosystem: C.1
lifetime elision (bootstrap + selfhost), bux fmt/test/doc CI hooks,
stdlib goldens, package registry (bux search/add), and LSP 0.4
position-sensitive locals with inferred let types. Full-tree format
pass plus Map/Set remove double-free fix.

tests/golden/enums/src/Main.bux

@@ -23,12 +23,12 @@ func ColorName(c: Color) -> String {
 
 func Main() -> int {
     let myColor: Color = Color::Green;
-    
+
     PrintLine("My color is:");
     PrintLine(ColorName(myColor));
     PrintLine("Color value:");
     PrintInt(myColor as int);
     PrintLine("");
-    
+
     return 0;
 }