feat(#125): rename GITEA_URL to VCS_URL with deprecated fallback

- Add --vcs-url flag as primary (reads VCS_URL env var)
- Keep --gitea-url and GITEA_URL as deprecated fallbacks with warnings
- Update action.yml: rename gitea-url input to vcs-url, pass VCS_URL to binary
- Update ci.yml: use VCS_URL env var in Run review step
- Update integration tests: INTEGRATION_GITEA_URL -> INTEGRATION_VCS_URL
- Update README: --vcs-url / VCS_URL with fallback note in env var table

Backward compat: existing GITEA_URL users get a deprecation warning and
continue to work unchanged until they migrate to VCS_URL.

.gitea/actions/review/action.yml

@@ -6,8 +6,8 @@ name: 'AI Code Review'
 description: 'Run AI-powered code review on a pull request using review-bot'
 
 inputs:
-  gitea-url:
-    description: 'Gitea instance URL (defaults to server_url)'
+  vcs-url:
+    description: 'VCS server URL (defaults to server_url)'
     required: false
     default: ''
   repo:
@@ -112,11 +112,11 @@ runs:
       id: version
       shell: bash
       run: |
-        GITEA_URL="${{ inputs.gitea-url || github.server_url }}"
+        BASE_URL="${{ inputs.vcs-url || github.server_url }}"
         REPO="${{ inputs.repo || 'rodin/review-bot' }}"
         if [ "${{ inputs.version }}" = "latest" ]; then
-          VERSION=$(curl -sSf "${GITEA_URL}/api/v1/repos/${REPO}/releases?limit=1" \
-            | python3 -c "import sys, json; releases = json.load(sys.stdin); print(releases[0]['tag_name'] if releases else '')")
+          VERSION=$(curl -sSf "${BASE_URL}/api/v1/repos/${REPO}/releases?limit=1" \
+            | python3 -c "import sys, json; releases = json.load(sys.stdin); print(releases[0]['tag_name'] if releases else '')") 
           if [ -z "$VERSION" ]; then
             echo "Failed to determine latest version" >&2
             exit 1
@@ -161,14 +161,14 @@ runs:
       if: steps.cache.outputs.cache-hit != 'true'
       shell: bash
       run: |
-        GITEA_URL="${{ inputs.gitea-url || github.server_url }}"
+        BASE_URL="${{ inputs.vcs-url || github.server_url }}"
         REPO="${{ inputs.repo || 'rodin/review-bot' }}"
         VERSION="${{ steps.version.outputs.version }}"
         BINARY="review-bot-${{ steps.version.outputs.os }}-${{ steps.version.outputs.arch }}"
 
-        curl -sSfL "${GITEA_URL}/${REPO}/releases/download/${VERSION}/${BINARY}" \
+        curl -sSfL "${BASE_URL}/${REPO}/releases/download/${VERSION}/${BINARY}" \
           -o "${{ runner.temp }}/review-bot"
-        curl -sSfL "${GITEA_URL}/${REPO}/releases/download/${VERSION}/checksums.txt" \
+        curl -sSfL "${BASE_URL}/${REPO}/releases/download/${VERSION}/checksums.txt" \
           -o "${{ runner.temp }}/checksums.txt"
 
         # Verify SHA-256 checksum
@@ -198,7 +198,7 @@ runs:
     - name: Run review
       shell: bash
       env:
-        GITEA_URL: ${{ inputs.gitea-url || github.server_url }}
+        VCS_URL: ${{ inputs.vcs-url || github.server_url }}
         GITEA_REPO: ${{ inputs.repo || github.repository }}
         PR_NUMBER: ${{ inputs.pr-number || github.event.pull_request.number }}
         REVIEWER_TOKEN: ${{ inputs.reviewer-token }}

.gitea/workflows/ci.yml

@@ -49,7 +49,7 @@ jobs:
       - run: go build -o review-bot ./cmd/review-bot
       - name: Run ${{ matrix.name }} review
         env:
-          GITEA_URL: ${{ github.server_url }}
+          VCS_URL: ${{ github.server_url }}
           GITEA_REPO: ${{ github.repository }}
           PR_NUMBER: ${{ github.event.pull_request.number }}
           REVIEWER_TOKEN: ${{ secrets[matrix.token_secret] }}