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/modern_features/src/Main.bux

@@ -1,49 +1,49 @@
 module Main {
 
-import Std::Array::{Array, Array_New, Array_Push};
+    import Std::Array::{Array, Array_New, Array_Push};
 
-struct Record {
-    name: String;
-    value: int;
-}
-
-struct Box {
-    items: Array<Record>;
-}
-
-enum Payload {
-    Ok(Record),
-    Err(String),
-}
-
-enum Color { Red, Green }
-
-func Name(c: Color) -> String {
-    match c {
-        Color::Red   => "red",
-        Color::Green => "green",
+    struct Record {
+        name: String;
+        value: int;
     }
-}
 
-func Main() -> int {
-    var box: Box;
-    box.items = Array_New<Record>(4);
-    Array_Push<Record>(&box.items, Record { name: "x", value: 10 });
+    struct Box {
+        items: Array<Record>;
+    }
 
-    for it in box.items {
-        if it.value == 10 {
-            return 0;
+    enum Payload {
+        Ok(Record),
+        Err(String),
+    }
+
+    enum Color { Red, Green }
+
+    func Name(c: Color) -> String {
+        match c {
+            Color::Red   => "red",
+            Color::Green => "green",
         }
     }
 
-    var r: Payload;
-    r.tag = Payload_Ok;
-    r.data.Ok_0 = Record { name: "y", value: 20 };
-    if r.data.Ok_0.value == 20 {
-        return 0;
+    func Main() -> int {
+        var box: Box;
+        box.items = Array_New<Record>(4);
+        Array_Push<Record>(&box.items, Record { name: "x", value: 10 });
+
+        for it in box.items {
+            if it.value == 10 {
+                return 0;
+            }
+        }
+
+        var r: Payload;
+        r.tag = Payload_Ok;
+        r.data.Ok_0 = Record { name: "y", value: 20 };
+        if r.data.Ok_0.value == 20 {
+            return 0;
+        }
+
+        return 1;
     }
 
-    return 1;
-}
-
 }