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/services/lfs/lfs-agent-service.ts

@@ -0,0 +1,59 @@
+import fs from 'node:fs';
+import path from 'node:path';
+import { OrchestratorSystem } from '../core/orchestrator-system';
+import OrchestratorLogger from '../core/orchestrator-logger';
+
+export class LfsAgentService {
+  /**
+   * Configure a custom LFS transfer agent in a git repository.
+   * Sets up the git config entries and environment variables needed for the agent.
+   */
+  static async configure(
+    agentPath: string,
+    agentArgs: string,
+    storagePaths: string[],
+    repoPath: string,
+  ): Promise<void> {
+    // Validate the agent executable exists
+    if (!fs.existsSync(agentPath)) {
+      OrchestratorLogger.logWarning(
+        `[LfsAgent] Agent executable not found at ${agentPath}, continuing without custom LFS agent`,
+      );
+
+      return;
+    }
+
+    // Derive agent name from executable filename (without extension)
+    const agentName = path.basename(agentPath, path.extname(agentPath));
+
+    OrchestratorLogger.log(`[LfsAgent] Configuring custom LFS transfer agent: ${agentName}`);
+    OrchestratorLogger.log(`[LfsAgent]   Path: ${agentPath}`);
+    OrchestratorLogger.log(`[LfsAgent]   Args: ${agentArgs}`);
+
+    // Set git config entries for the custom transfer agent
+    await OrchestratorSystem.Run(`git -C "${repoPath}" config lfs.customtransfer.${agentName}.path "${agentPath}"`);
+    await OrchestratorSystem.Run(`git -C "${repoPath}" config lfs.customtransfer.${agentName}.args "${agentArgs}"`);
+    await OrchestratorSystem.Run(`git -C "${repoPath}" config lfs.standalonetransferagent ${agentName}`);
+
+    // Set storage paths environment variable if provided
+    if (storagePaths.length > 0) {
+      const storagePathsValue = storagePaths.join(';');
+      process.env.LFS_STORAGE_PATHS = storagePathsValue;
+      OrchestratorLogger.log(`[LfsAgent]   Storage paths: ${storagePathsValue}`);
+    }
+
+    OrchestratorLogger.log(`[LfsAgent] Custom LFS transfer agent configured successfully`);
+  }
+
+  /**
+   * Validate that the LFS transfer agent executable exists.
+   */
+  static async validate(agentPath: string): Promise<boolean> {
+    const exists = fs.existsSync(agentPath);
+    if (!exists) {
+      OrchestratorLogger.logWarning(`[LfsAgent] Agent executable not found: ${agentPath}`);
+    }
+
+    return exists;
+  }
+}