feat(ui): generate dashboard API types from the proxy OpenAPI spec (#29816)

* feat(ui): generate dashboard API types from the proxy OpenAPI spec

Introduces the shared type foundation for the dashboard without touching any
runtime code. The proxy's FastAPI app is the source of truth; app.openapi()
emits the spec and openapi-typescript turns it into src/lib/http/schema.d.ts.

Adds an npm run gen:api script (a Python spec dump piped into openapi-typescript)
and a Check UI API Types Sync CI job that regenerates the file from the live
spec and fails if it drifts, so the committed types can never silently fall out
of step with the backend. The generated file is pinned to openapi-typescript
7.13.0 and excluded from prettier, eslint, and knip, and marked linguist-generated
so it collapses in diffs.

No openapi-fetch and no call-site changes yet; this only makes the types exist.

* chore(ui): tidy gen-api-types script per review

Write the spec dump inside a with-block and clean up the temp dir in a
finally, so repeated local runs don't leave stray ~MB JSON files behind.

.github/workflows/check-ui-api-types.yml

@@ -0,0 +1,84 @@
+name: Check UI API Types Sync
+
+on:
+  pull_request:
+    paths:
+      - "litellm/proxy/**"
+      - "litellm/types/**"
+      - "ui/litellm-dashboard/src/lib/http/schema.d.ts"
+      - "ui/litellm-dashboard/scripts/gen-api-types.mjs"
+      - "ui/litellm-dashboard/package.json"
+      - "ui/litellm-dashboard/package-lock.json"
+      - ".github/workflows/check-ui-api-types.yml"
+
+permissions:
+  contents: read
+
+jobs:
+  check-sync:
+    name: Verify schema.d.ts matches the proxy OpenAPI spec
+    runs-on: ubuntu-latest
+    timeout-minutes: 15
+    steps:
+      - name: Checkout repository
+        uses: actions/checkout@08eba0b27e820071cde6df949e0beb9ba4906955 # v4.3.0
+        with:
+          persist-credentials: false
+
+      - name: Set up Python
+        uses: actions/setup-python@a26af69be951a213d495a4c3e4e4022e16d87065 # v5.6.0
+        with:
+          python-version: "3.12"
+
+      - name: Set up uv
+        uses: astral-sh/setup-uv@37802adc94f370d6bfd71619e3f0bf239e1f3b78 # v7
+        with:
+          version: "0.10.9"
+
+      - name: Cache uv dependencies
+        uses: actions/cache@0057852bfaa89a56745cba8c7296529d2fc39830 # v4.3.0
+        with:
+          path: |
+            ~/.cache/uv
+            .venv
+          key: ${{ runner.os }}-uv-${{ hashFiles('uv.lock') }}
+          restore-keys: |
+            ${{ runner.os }}-uv-
+
+      - name: Install backend dependencies
+        run: uv sync --frozen --group ci --group proxy-dev --extra google --extra proxy --extra semantic-router
+
+      - name: Generate Prisma client
+        env:
+          PRISMA_BINARY_CACHE_DIR: ${{ runner.temp }}/prisma-cache
+        run: uv run --no-sync prisma generate --schema litellm/proxy/schema.prisma
+
+      - name: Set up Node.js
+        uses: actions/setup-node@a0853c24544627f65ddf259abe73b1d18a591444 # v5.0
+        with:
+          node-version: "20"
+          cache: "npm"
+          cache-dependency-path: ui/litellm-dashboard/package-lock.json
+
+      - name: Install dashboard dependencies
+        working-directory: ui/litellm-dashboard
+        run: npm ci
+
+      - name: Regenerate types from the live spec
+        working-directory: ui/litellm-dashboard
+        env:
+          LITELLM_PYTHON: "uv run --no-sync python"
+        run: npm run gen:api
+
+      - name: Fail if types are stale
+        run: |
+          if ! git diff --exit-code -- ui/litellm-dashboard/src/lib/http/schema.d.ts; then
+            echo "::error file=ui/litellm-dashboard/src/lib/http/schema.d.ts::Generated API types are out of sync with the proxy OpenAPI spec."
+            echo ""
+            echo "A backend route or model changed without regenerating the dashboard types."
+            echo "To fix, run from ui/litellm-dashboard:"
+            echo "  npm run gen:api"
+            echo "then commit the updated src/lib/http/schema.d.ts."
+            exit 1
+          fi
+          echo "schema.d.ts is in sync with the proxy OpenAPI spec."