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/algebraic_enums/src/Main.bux

@@ -10,20 +10,20 @@ enum Result {
 func Main() -> int {
     let r1: Result = Result { tag: Result_Ok };
     r1.data.Ok_0 = 42;
-    
+
     let r2: Result = Result { tag: Result_Err };
     r2.data.Err_0 = "error message";
-    
+
     if r1.tag == Result_Ok {
         PrintLine("r1 is Ok:");
         PrintInt(r1.data.Ok_0);
         PrintLine("");
     }
-    
+
     if r2.tag == Result_Err {
         PrintLine("r2 is Err:");
         PrintLine(r2.data.Err_0);
     }
-    
+
     return 0;
 }