Select changed and related tests from the module graph

Summary

Let GocciaTestRunner select test files related to explicit source files or to files changed from a version-control reference.

Why

Large suites need a deterministic one-shot way to run the tests affected by a change without executing every test file. The project already has module resolution and graph-aware work planned for 0.13.0, making this the appropriate seam for dependency-based selection.

Current behavior

The runner expands supplied files and directories and executes all discovered script files. It does not construct a test-to-module dependency map or consult version-control changes.

Expected behavior

• Select tests related to one or more explicitly supplied source modules.
• Select tests related to files changed from a supplied Git reference, with a documented default reference.
• Use GocciaScript's actual module resolution rules, including aliases, import maps, and supported virtual-module identities.
• Handle added, modified, renamed, and deleted paths predictably.
• Keep selection deterministic across interpreter/bytecode modes and local --jobs values.
• Report the selected test-file set in human-readable and structured output.

Scope notes

• Base selection on the static module graph; runtime tracing of dynamic dependencies is not required.
• Watch mode is a separate persistent-runner issue that can reuse this selector.
• Do not introduce Node/npm resolution, a Vite dependency graph, or a distributed test service.
• Test-name and source-line filtering remain a registration-level concern.

Start at GocciaTestRunner and the project's existing module-resolution implementation. Define the static dependency-based selector around those seams, then verify that explicit sources and Git changes select deterministic test sets and that human-readable and structured reports cover the stated path cases.