fix(ci): 改用 self-hosted runner (GitHub 帳單問題)

問題:
- CI workflow 不知何時被改成 ubuntu-latest
- 導致 GitHub Actions 因帳單問題失敗

修復:
- 全部改回 self-hosted (awoooi-110)

鐵律:
- Memory 記錄: feedback_github_billing.md
- 禁止使用 GitHub 雲端 Runner

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

.github/workflows/ci.yaml

@@ -15,7 +15,7 @@ jobs:
   # ==================== Lint & Type Check ====================
   lint:
     name: Lint & Type Check
-    runs-on: ubuntu-latest
+    runs-on: self-hosted
     steps:
       - uses: actions/checkout@v4
 
@@ -72,7 +72,7 @@ jobs:
   # ==================== Test ====================
   test:
     name: Test
-    runs-on: ubuntu-latest
+    runs-on: self-hosted
     needs: lint
     steps:
       - uses: actions/checkout@v4
@@ -103,7 +103,7 @@ jobs:
   # ==================== Build ====================
   build:
     name: Build
-    runs-on: ubuntu-latest
+    runs-on: self-hosted
     needs: lint
     steps:
       - uses: actions/checkout@v4
@@ -140,7 +140,7 @@ jobs:
   # ==================== API (Python) ====================
   api-lint:
     name: API Lint (Python)
-    runs-on: ubuntu-latest
+    runs-on: self-hosted
     steps:
       - uses: actions/checkout@v4
 
@@ -166,7 +166,7 @@ jobs:
 
   api-test:
     name: API Test (Python)
-    runs-on: ubuntu-latest
+    runs-on: self-hosted
     needs: api-lint
     steps:
       - uses: actions/checkout@v4
@@ -190,7 +190,7 @@ jobs:
   # ==================== OpenAPI Validation ====================
   openapi-validate:
     name: Validate OpenAPI Spec
-    runs-on: ubuntu-latest
+    runs-on: self-hosted
     steps:
       - uses: actions/checkout@v4
 
@@ -208,7 +208,7 @@ jobs:
   # ==================== Docker Build (驗證 Dockerfile) ====================
   docker-build:
     name: Docker Build Verify
-    runs-on: ubuntu-latest
+    runs-on: self-hosted
     needs: [test, api-test, build]
     strategy:
       matrix: