Add CollapseWebPaths test: transitive-dependency res must be registered

[beaucollins]

Adds a CollapseWebPaths unit test that documents a regression on this branch (#148): transitive-dependency res/ images are copied into the web package but never registered in _image_registry.js, so getAssets() can't resolve them at runtime and the icons render blank.

Root cause

valdi/compiler/toolbox/src/valdi/compiler_toolbox/CollapseWebPaths.cpp generateImageRegistry (L274) scans only the immediate children of src/ for <module>/res (DiskUtils::listDirectory(sourceDirectory), L276). The collapse stages direct-dep res at top-level src/<module>/res (registered) but transitive-dep res at a nested src/release/res/<module>/res (never scanned). Observed on a real package: only the direct module appeared in _image_registry.js; ~20 coreui icons and other transitive res were bundled but unregistered.

Repro

TEST(CollapseWebPaths, registersTransitiveDependencyResources) builds a package with a direct-dep res and a transitive-dep res (staged under release/res/shared/res) and asserts both appear in the registry. It fails on this branch because the transitive entry is dropped.

Suggested fix

Enumerate res under the nested release/res/<module>/res locations too (or stage all module res uniformly at src/<module>/res), so the registry matches the full transitive web-dep closure.

[github-actions]

📊 PR Size: size/S

Total changes: 39 lines (1 files)

Top files changed:

• valdi/compiler/toolbox/test/CollapseWebPaths_tests.cpp: +39 -0

_{Size calculated as additions + deletions. Labels: XS (<10), S (<50), M (<250), L (<1000), XL (1000+)}

[github-actions]

⚠️ Bazel & CI Test Results

Test Suite	Result
API Surface Check	✅ success
Linux: Module Tests	✅ success
valdi_web Integration Test	❌ failure
Snapshot Tests	✅ success
Valdi Smoke Tests	✅ success
Linux: Build & Export	✅ success
Linux: C++ Tests	❌ failure
Linux: Hotreload Smoke	✅ success
Linux: Build Compiler	✅ success
macOS: C++ & Platform Tests	✅ success
Linux: Registry Validation	✅ success

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