Copy Flutter dep assets/shaders/fonts into .clojuredart/deps stubs

[dankinsoid]

Problem

sync-pubspec! mirrors each Flutter dependency into .clojuredart/deps/<sha>/ as a bare pubspec.yaml stub. Flutter's asset bundler reads that stub's flutter: section and resolves the declared assets/shaders/fonts relative to it (asset.dart _parseAssets runs per-package). But the stub only ever contained the pubspec — never the files it references.

So a package that ships shaders or assets — e.g. a widget lib that does

FragmentProgram.fromAsset("packages/my_pkg/shaders/gradient.frag")

gets nothing bundled under packages/my_pkg/… and fails at runtime (missing shader/asset). There's no way to fix this from the consuming app's pubspec, because the shaders live at the dep's package root, not under lib/. Today the only workaround is a post-compile script that copies the files into every stub by hand.

Fix

When materializing a stub, also copy the files the dep declares under flutter: {assets, shaders, fonts} from its source checkout into the stub dir. Source dir is resolved from the already-available coordinate (:deps/root for git / :local/root, or a directory on :paths); jar-only deps are a no-op.

• Trailing-slash asset entries (directory wildcards) are copied recursively.
• Map-form asset entries ({path: …, flavors: …}) and fonts: [{fonts: [{asset: …}]}] are handled.
• No-op when the source dir is unknown or the dep declares no flutter: bundle.

Runs inside the existing deps-to-add loop, so it only fires when a dep is (re)materialized.

Testing

Loaded cljd.build to confirm it compiles, and unit-tested copy-flutter-assets! against a fixture covering shaders, single assets, wildcard directories, fonts, map-form entries, missing-file skip, and nil src/flutter guards — all pass.

🤖 Generated with Claude Code

[dankinsoid]

Duplicate of #378 — consolidated there (that one keeps find-pubspec's search precise for multi-path deps and carries the fonts handling from here). Closing this one.