fix(resolution): Svelte/Vue component resolvers get the #764 ambiguity rule (#814)

Follow-up to #813: the React resolver's blind components[0] fallback was
the demonstrated wrong-edge source, but the Svelte and Vue resolvers had
the same flaw in their own shape:

- svelte: resolveComponent fell back to components[0] across the whole
  repo when no same-directory match existed — an arbitrary pick among
  same-named components in a multi-app monorepo.
- vue: resolveComponent returned the FIRST basename-matching .vue file
  found anywhere in the tree; its same-directory pass below was
  unreachable dead code. apps/a/Button.vue vs apps/b/Button.vue was a
  file-enumeration-order coin flip.

Both now follow the #764 rule: same-directory first, otherwise only an
UNAMBIGUOUS name resolves — ambiguity falls through to the name-matcher's
proximity scoring instead of guessing.

Safety: zero-delta A/B on the README's own framework benchmark repos
(sveltejs/realworld — the 100% Svelte coverage repo — and nuxt/movies,
93.5% Vue coverage) plus the excalidraw control: node counts identical,
zero calls or references edges changed. Single-app repos have unique
component names, so the rule only bites where the old behavior was
already a coin flip. Full suite 1398 passed.

Also verified the #813 per-definition tool grouping is language-agnostic
(probed Go same-named functions across packages — grouped identically to
the TS fixture).

Co-authored-by: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

src/resolution/frameworks/svelte.ts

@@ -220,7 +220,11 @@ function resolveComponent(
   const sameDir = components.filter((n) => n.filePath.startsWith(fromDir));
   if (sameDir.length > 0) return sameDir[0]!.id;
 
-  return components[0]!.id;
+  // No positional signal: only an UNAMBIGUOUS name may resolve — picking
+  // components[0] chose an arbitrary same-named component in a multi-app
+  // monorepo (#764). Ambiguity falls through to the name-matcher, whose
+  // proximity scoring decides.
+  return components.length === 1 ? components[0]!.id : null;
 }
 
 /**

src/resolution/frameworks/vue.ts

@@ -279,39 +279,32 @@ function resolveComponent(
   fromFile: string,
   context: ResolutionContext
 ): string | null {
-  const allFiles = context.getAllFiles();
-  const vueFiles = allFiles.filter((f) => f.endsWith('.vue'));
-
-  // Check for exact name match (Button -> Button.vue)
-  for (const file of vueFiles) {
+  // Collect ALL basename matches first. The previous version returned the
+  // FIRST `Button.vue` found anywhere in the tree (its same-directory pass
+  // below was unreachable), so a multi-app monorepo with one `Button.vue`
+  // per app resolved to an arbitrary one (#764).
+  const matches: string[] = [];
+  for (const file of context.getAllFiles()) {
+    if (!file.endsWith('.vue')) continue;
     const fileName = file.split(/[/\\]/).pop() || '';
-    const componentName = fileName.replace(/\.vue$/, '');
-    if (componentName === name) {
-      const nodes = context.getNodesInFile(file);
-      const component = nodes.find((n) => n.kind === 'component' && n.name === name);
-      if (component) {
-        return component.id;
-      }
-    }
+    if (fileName.replace(/\.vue$/, '') === name) matches.push(file);
   }
+  if (matches.length === 0) return null;
 
-  // Check same directory first for better specificity
+  const componentIn = (file: string): string | null => {
+    const nodes = context.getNodesInFile(file);
+    const component = nodes.find((n) => n.kind === 'component' && n.name === name);
+    return component ? component.id : null;
+  };
+
+  // Same directory first for specificity
   const fromDir = fromFile.substring(0, fromFile.lastIndexOf('/'));
-  for (const file of vueFiles) {
-    if (file.startsWith(fromDir)) {
-      const fileName = file.split(/[/\\]/).pop() || '';
-      const componentName = fileName.replace(/\.vue$/, '');
-      if (componentName === name) {
-        const nodes = context.getNodesInFile(file);
-        const component = nodes.find((n) => n.kind === 'component');
-        if (component) {
-          return component.id;
-        }
-      }
-    }
-  }
+  const sameDir = matches.filter((f) => f.startsWith(fromDir));
+  if (sameDir.length > 0) return componentIn(sameDir[0]!);
 
-  return null;
+  // No positional signal: only an UNAMBIGUOUS basename may resolve;
+  // ambiguity falls through to the name-matcher's proximity scoring.
+  return matches.length === 1 ? componentIn(matches[0]!) : null;
 }
 
 /**