ci: make public OCR reviews manual and hosted

Why:
Public pull requests should not automatically schedule review work on a persistent self-hosted runner.

Changed:
- Run OCR on ubuntu-latest.
- Accept only explicit review commands from authorized repository members.
- Remove the pull_request_target path and unused event handling.

Verification:
- actionlint v1.7.7
- npm run agent:verify -- --profile spec-only --paths .github/workflows/ocr-review.yml

Affected:
- .github/workflows/ocr-review.yml

Refs:
- Public Actions runner hardening

Session:
- task-sessions/20260820-public-ocr-hosted-manual

Author: VladimirBrejcha

.github/workflows/ocr-review.yml

@@ -1,4 +1,4 @@
-# OpenCodeReview PR auto-review — self-contained workflow for PUBLIC repos.
+# OpenCodeReview PR on-demand review — self-contained workflow for PUBLIC repos.
 # GitHub only lets public caller repos invoke PUBLIC reusable workflows, so
 # simulator-broker / agent-skills cannot call the private
 # fiveonecode/workflows reusable. This file inlines the proven job body from
@@ -11,31 +11,23 @@ name: OpenCodeReview PR Review
 concurrency:
   group: >-
     ${{
-      (
-        github.event_name == 'pull_request_target'
-        || (
-          github.event_name == 'issue_comment'
-          && github.event.issue.pull_request
-          && github.event.comment.user.type != 'Bot'
-          && (
-            github.event.comment.author_association == 'MEMBER'
-            || github.event.comment.author_association == 'OWNER'
-            || github.event.comment.author_association == 'COLLABORATOR'
-          )
-          && (
-            startsWith(github.event.comment.body, '/open-code-review')
-            || startsWith(github.event.comment.body, '@open-code-review')
-          )
-        )
+      github.event.issue.pull_request
+      && github.event.comment.user.type != 'Bot'
+      && (
+        github.event.comment.author_association == 'MEMBER'
+        || github.event.comment.author_association == 'OWNER'
+        || github.event.comment.author_association == 'COLLABORATOR'
       )
-      && format('ocr-{0}', github.event.pull_request.number || github.event.issue.number)
+      && (
+        startsWith(github.event.comment.body, '/open-code-review')
+        || startsWith(github.event.comment.body, '@open-code-review')
+      )
+      && format('ocr-{0}', github.event.issue.number)
       || format('noop-{0}', github.run_id)
     }}
   cancel-in-progress: true
 
 on:
-  pull_request_target:
-    types: [opened, synchronize, reopened]
   issue_comment:
     types: [created]
 
@@ -46,52 +38,37 @@ permissions:
 jobs:
   code-review:
     if: |
-      github.event_name == 'pull_request_target'
-      || (
-        github.event_name == 'issue_comment'
-        && github.event.issue.pull_request
-        && github.event.comment.user.type != 'Bot'
-        && (
-          github.event.comment.author_association == 'MEMBER'
-          || github.event.comment.author_association == 'OWNER'
-          || github.event.comment.author_association == 'COLLABORATOR'
-        )
-        && (
-          startsWith(github.event.comment.body, '/open-code-review')
-          || startsWith(github.event.comment.body, '@open-code-review')
-        )
+      github.event.issue.pull_request
+      && github.event.comment.user.type != 'Bot'
+      && (
+        github.event.comment.author_association == 'MEMBER'
+        || github.event.comment.author_association == 'OWNER'
+        || github.event.comment.author_association == 'COLLABORATOR'
+      )
+      && (
+        startsWith(github.event.comment.body, '/open-code-review')
+        || startsWith(github.event.comment.body, '@open-code-review')
       )
-    # Self-hosted; the org runner group is granted access to this public repo and
-    # forking is restricted so untrusted forks cannot schedule workflow runs here.
-    runs-on: self-hosted
+    # Public-repository reviews run only after an authorized member requests one,
+    # on GitHub's free, ephemeral standard runner.
+    runs-on: ubuntu-latest
     timeout-minutes: 240
     steps:
       - name: Get PR context
         id: pr-context
         uses: actions/github-script@v7
         with:
           script: |
-            let baseRef, headSha, title, prNumber;
-            if (context.eventName === 'issue_comment') {
-              prNumber = context.issue.number;
-              const { data: pr } = await github.rest.pulls.get({
-                owner: context.repo.owner,
-                repo: context.repo.repo,
-                pull_number: prNumber,
-              });
-              baseRef = pr.base.ref;
-              headSha = pr.head.sha;
-              title = pr.title;
-            } else {
-              prNumber = context.payload.pull_request.number;
-              baseRef = context.payload.pull_request.base.ref;
-              headSha = context.payload.pull_request.head.sha;
-              title = context.payload.pull_request.title;
-            }
+            const prNumber = context.issue.number;
+            const { data: pr } = await github.rest.pulls.get({
+              owner: context.repo.owner,
+              repo: context.repo.repo,
+              pull_number: prNumber,
+            });
             core.setOutput('pr_number', String(prNumber));
-            core.setOutput('base_ref', baseRef);
-            core.setOutput('head_sha', headSha);
-            core.setOutput('title', title);
+            core.setOutput('base_ref', pr.base.ref);
+            core.setOutput('head_sha', pr.head.sha);
+            core.setOutput('title', pr.title);
 
       - name: Checkout base (trusted)
         uses: actions/checkout@v4
@@ -195,4 +172,4 @@ jobs:
               stickySummary: true,
               incremental: true,
               incrementalOverlapThreshold: parseFloat(process.env.OCR_INCREMENTAL_OVERLAP_THRESHOLD),
-            });
+            });