feat(orchestrator): enterprise feature support — CLI provider, submodule profiles, caching, LFS, hooks

Add generic enterprise-grade features to the orchestrator, enabling Unity projects with
complex CI/CD pipelines to adopt game-ci/unity-builder with built-in support for:

- CLI provider protocol: JSON-over-stdin/stdout bridge enabling providers in any language
  (Go, Python, Rust, shell) via the `providerExecutable` input
- Submodule profiles: YAML-based selective submodule initialization with glob patterns
  and variant overlays (`submoduleProfilePath`, `submoduleVariantPath`)
- Local build caching: Filesystem-based Library and LFS caching for local builds without
  external cache actions (`localCacheEnabled`, `localCacheRoot`)
- Custom LFS transfer agents: Register external transfer agents like elastic-git-storage
  (`lfsTransferAgent`, `lfsTransferAgentArgs`, `lfsStoragePaths`)
- Git hooks support: Detect and install lefthook/husky with configurable skip lists
  (`gitHooksEnabled`, `gitHooksSkipList`)

Also removes all `orchestrator-develop` branch references, replacing with `main`.

13 new action inputs, 13 new files, 14 new CLI provider tests, 17 submodule tests,
plus cache/LFS/hooks unit tests. All 452 tests pass.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

src/model/orchestrator/workflows/build-automation-workflow.ts

@@ -99,8 +99,7 @@ if [ -n "$(git ls-remote --heads "$REPO" "$BRANCH" 2>/dev/null)" ]; then
   git clone -q -b "$BRANCH" "$REPO" "$DEST"
 else
   echo "Remote branch $BRANCH not found in $REPO; falling back to a known branch"
-  git clone -q -b orchestrator-develop "$REPO" "$DEST" \
-    || git clone -q -b main "$REPO" "$DEST" \
+  git clone -q -b main "$REPO" "$DEST" \
     || git clone -q "$REPO" "$DEST"
 fi
 chmod +x ${builderPath}`;