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>

.github/workflows/orchestrator-async-checks.yml

@@ -54,7 +54,7 @@ jobs:
           # AWS_STACK_NAME: game-ci-github-pipelines
           CHECKS_UPDATE: ${{ github.event.inputs.checksObject }}
         run: |
-          git clone -b orchestrator-develop https://github.com/game-ci/unity-builder
+          git clone -b main https://github.com/game-ci/unity-builder
           cd unity-builder
           yarn
           ls