fix(native): remove orphaned protoMethodsMs type and unify timer precision

Remove the `protoMethodsMs` optional field from `BuildResult.phases` that
was declared in types.ts but never populated by the orchestrator, report
script, or PostPassTimings interface — preventing it from silently appearing
as an always-undefined field in IDE autocomplete.

Migrate `runPostNativeThisDispatch` from `Date.now()` (integer ms) to
`performance.now()` (sub-ms float) so all five post-pass timings in
`PostPassTimings` use the same timer API and resolution.

Author: carlos-alm

src/domain/graph/builder/stages/native-orchestrator.ts

@@ -702,7 +702,7 @@ async function runPostNativeThisDispatch(
   changedFiles: string[] | undefined,
   isFullBuild: boolean,
 ): Promise<{ elapsedMs: number; targetIds: Set<number>; affectedFiles: Set<string> }> {
-  const t0 = Date.now();
+  const t0 = performance.now();
   const targetIds = new Set<number>();
   // Files containing endpoints of newly inserted edges — lets the caller scope
   // role re-classification to the nodes whose fan-in/out actually changed.
@@ -934,7 +934,7 @@ async function runPostNativeThisDispatch(
     (symbols as { _tree?: unknown; _langId?: unknown })._langId = undefined;
   }
 
-  return { elapsedMs: Date.now() - t0, targetIds, affectedFiles };
+  return { elapsedMs: performance.now() - t0, targetIds, affectedFiles };
 }
 
 interface PostPassTimings {

src/types.ts

@@ -1268,8 +1268,6 @@ export interface BuildResult {
     edgesMs: number;
     structureMs: number;
     rolesMs: number;
-    /** Wall-clock time for the prototype-method post-pass (native path only). */
-    protoMethodsMs?: number;
     /** Wall-clock time for the CHA expansion post-pass (native path only). */
     chaMs?: number;
     /** Wall-clock time for the this/super dispatch WASM post-pass (native path only). */