feat(orchestrator): middleware pipeline — composable trigger-aware hooks

Add a middleware system that wraps around build pipeline phases with
before/after semantics, built on the existing command hook and container
hook fundamentals. Middleware supports rich trigger conditions (phase,
provider, platform, environment expressions), priority-based ordering
with wrapping semantics, and both inline YAML and file-based definitions
from game-ci/middleware/.

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

src/model/orchestrator/options/orchestrator-options.ts

@@ -166,6 +166,14 @@ class OrchestratorOptions {
     return OrchestratorOptions.getInput('commandHookFiles')?.split(`,`) || [];
   }
 
+  static get middleware(): string {
+    return OrchestratorOptions.getInput('middleware') || '';
+  }
+
+  static get middlewareFiles(): string[] {
+    return OrchestratorOptions.getInput('middlewareFiles')?.split(',') || [];
+  }
+
   // ### ### ###
   // Custom commands from yaml parameters
   // ### ### ###