fix(resolution): resolve cross-file static method calls to the method, not the class (#825)

[maxmilian]

Fixes #825.

Problem

A cross-file static method call resolves to the class, not the method, and is then recorded as a construction:

// helpers.ts
export class Foo { static bar(x: number) { return x + 1; } }
// caller.ts
import { Foo } from './helpers';
export function run() { return Foo.bar(41); }

codegraph callers "Foo.bar" → empty. run ends up with a single instantiates → Foo edge and no calls → Foo::bar, so callers/impact for the static method are empty (false negatives) and the CLI's bare-name fallback surfaces unrelated same-named symbols (false positives).

Root cause

In resolveViaImport (src/resolution/import-resolver.ts), the generic named-import loop matches ref.referenceName.startsWith(imp.localName + '.') for the ref Foo.bar. For a non-namespace import memberName is left null, so findExportedSymbol returns the class Foo. resolveViaImport returns that at confidence 0.9, and resolveOne returns immediately — so the name-matcher's matchMethodCall (which already resolves Foo.bar → Foo::bar via its class-name strategy) never runs. createEdges then promotes the calls edge to instantiates because the target is a class, dropping the method.

So the calls → instantiates promotion is the relabel; the actual interception is the import resolver picking the class as the target. Guarding the promotion alone would leave the edge pointing at the class with the method still dropped — hence the fix is in the import resolver.

Fix

When the imported receiver is a class/struct and the calls ref is shaped localName.member, resolve the trailing member to that class's method (keyed on the exact owner segment of the qualifiedName, so a substring-named sibling like FooBar::bar can't soak the call) and return it — preserving the exact-file precision the import gives over a name-match fallback. If no matching method exists, behavior is unchanged. Genuine new Foo() construction is unaffected (still instantiates).

Tests

Added a regression test in __tests__/resolution.test.ts that locks:

• run --calls--> Foo::bar (exactly one edge), not mis-promoted to instantiates
• the call is not soaked into the substring-named sibling FooBar::bar
• getCallers(Foo::bar) surfaces run
• the new Foo() boundary still instantiates the class

Full suite green locally (npm run build && npm test): 1429 passed, 2 skipped.

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