refactor: extract orchestrator — delete 30k lines, decouple all imports

Remove the entire src/model/orchestrator/ directory (148 files, ~30k lines)
and refactor all dependent code to use the plugin loader pattern.

Key changes:
- build-parameters.ts: replace OrchestratorOptions with Input.getInput()
- input.ts: remove OrchestratorQueryOverride input source
- github.ts: strip to minimal class (only githubInputEnabled remains)
- cli/cli.ts: remove orchestrator CLI commands, simplify to core structure
- input-readers/*: replace OrchestratorSystem.Run with child_process.exec
- orchestrator-plugin.ts: import from @game-ci/orchestrator package
- orchestrate.ts, build.ts: use plugin loader instead of direct imports
- index.ts: inline SyncStrategy type, fix implicit any types
- Add type declarations for @game-ci/orchestrator
- Remove orchestrator-only npm dependencies (AWS SDK, K8s, etc.)
- Remove orchestrator-specific npm scripts and CI workflows
- Update validate-orchestrator.yml for external repo validation

All enterprise features gracefully degrade when @game-ci/orchestrator
is not installed — the plugin loader returns undefined and optional
chaining in index.ts skips all enterprise service calls.

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

package.json

@@ -31,18 +31,8 @@
     "format": "prettier --write \"src/**/*.{js,ts}\"",
     "cli": "yarn ts-node src/index.ts -m cli",
     "game-ci": "ts-node src/cli.ts",
-    "gcp-secrets-tests": "cross-env providerStrategy=aws orchestratorTests=true inputPullCommand=\"gcp-secret-manager\" populateOverride=true pullInputList=UNITY_EMAIL,UNITY_SERIAL,UNITY_PASSWORD yarn test -i -t \"orchestrator\"",
-    "gcp-secrets-cli": "cross-env orchestratorTests=true USE_IL2CPP=false inputPullCommand=\"gcp-secret-manager\" yarn ts-node src/index.ts -m cli --populateOverride true --pullInputList UNITY_EMAIL,UNITY_SERIAL,UNITY_PASSWORD",
-    "aws-secrets-cli": "cross-env orchestratorTests=true inputPullCommand=\"aws-secret-manager\" yarn ts-node src/index.ts -m cli --populateOverride true --pullInputList UNITY_EMAIL,UNITY_SERIAL,UNITY_PASSWORD",
-    "cli-aws": "cross-env providerStrategy=aws yarn run test-cli",
-    "cli-k8s": "cross-env providerStrategy=k8s yarn run test-cli",
-    "test-cli": "cross-env orchestratorTests=true yarn ts-node src/index.ts -m cli --projectPath test-project",
     "test": "jest",
-    "test:ci": "jest --config=jest.ci.config.js --runInBand",
-    "test-i": "cross-env orchestratorTests=true yarn test -i -t \"orchestrator\"",
-    "test-i-*": "yarn run test-i-aws && yarn run test-i-k8s",
-    "test-i-aws": "cross-env orchestratorTests=true providerStrategy=aws yarn test -i -t \"orchestrator\"",
-    "test-i-k8s": "cross-env orchestratorTests=true providerStrategy=k8s yarn test -i -t \"orchestrator\""
+    "test:ci": "jest --config=jest.ci.config.js --runInBand"
   },
   "engines": {
     "node": ">=18.x"
@@ -52,36 +42,21 @@
     "@actions/core": "^1.11.1",
     "@actions/exec": "^1.1.1",
     "@actions/github": "^6.0.0",
-    "@aws-sdk/client-cloudformation": "^3.777.0",
-    "@aws-sdk/client-cloudwatch-logs": "^3.777.0",
-    "@aws-sdk/client-ecs": "^3.778.0",
-    "@aws-sdk/client-kinesis": "^3.777.0",
-    "@aws-sdk/client-s3": "^3.779.0",
-    "@kubernetes/client-node": "^0.16.3",
-    "@octokit/core": "^5.1.0",
-    "async-wait-until": "^2.0.12",
-    "aws-sdk": "^2.1081.0",
-    "base-64": "^1.0.0",
     "commander": "^9.0.0",
     "commander-ts": "^0.2.0",
-    "kubernetes-client": "^9.0.0",
     "md5": "^2.3.0",
-    "nanoid": "^3.3.1",
     "reflect-metadata": "^0.1.13",
+    "nanoid": "^3.3.1",
     "semver": "^7.5.2",
-    "shell-quote": "^1.8.3",
     "ts-md5": "^1.3.1",
     "unity-changeset": "^3.1.0",
-    "uuid": "^9.0.0",
     "yaml": "^2.2.2",
     "yargs": "^17.7.2"
   },
   "devDependencies": {
-    "@types/base-64": "^1.0.0",
     "@types/jest": "^27.4.1",
     "@types/node": "^17.0.23",
     "@types/semver": "^7.3.9",
-    "@types/uuid": "^9.0.0",
     "@types/yargs": "^17.0.35",
     "@typescript-eslint/parser": "4.8.1",
     "@vercel/ncc": "^0.36.1",