Change Claude Code review to on-demand triggers (#25)

* Change Claude Code review to on-demand via @claude or review request

Replace automatic PR triggers (opened, ready_for_review) with on-demand
triggers: @claude mentions in PR comments, inline review comments, and
review requests from the 'claude' team.

* Remove unreachable workflow_call event check

workflow_call invocations inherit the caller's event_name, so
github.event_name == 'workflow_call' never matches. The caller's
event context passes through and is handled by the existing
issue_comment/review_requested conditions.

* Fix workflow_call invocations being silently skipped

Add a direct_call boolean input (defaults to true) to workflow_call
so reusable workflow callers bypass the event-specific filtering gate.
Without this, callers triggered by e.g. pull_request opened would
hit the pull_request branch which requires requested_team.slug == 'claude',
causing a silent no-op.

.github/workflows/claude-code-review.yaml

@@ -7,9 +7,18 @@ on:
         description: Pull request number to review
         required: true
         type: string
+  issue_comment:
+    types: [created]
+  pull_request_review_comment:
+    types: [created]
   pull_request:
-    types: [opened, ready_for_review]
+    types: [review_requested]
   workflow_call:
+    inputs:
+      direct_call:
+        description: Bypass event filtering (set automatically for reusable workflow callers)
+        type: boolean
+        default: true
     secrets:
       anthropic_api_key:
         required: true
@@ -17,11 +26,21 @@ on:
 permissions:
   contents: read
   pull-requests: write
+  issues: read
   id-token: write
 
 jobs:
   claude-review:
-    if: github.event.pull_request.draft == false
+    if: >-
+      (github.event_name == 'issue_comment' &&
+        contains(github.event.comment.body, '@claude') &&
+        github.event.issue.pull_request) ||
+      (github.event_name == 'pull_request_review_comment' &&
+        contains(github.event.comment.body, '@claude')) ||
+      (github.event_name == 'pull_request' &&
+        github.event.requested_team.slug == 'claude') ||
+      github.event_name == 'workflow_dispatch' ||
+      inputs.direct_call == true
     runs-on: ubuntu-latest
     timeout-minutes: 10
     steps:
@@ -33,9 +52,10 @@ jobs:
         with:
           anthropic_api_key: ${{ secrets.anthropic_api_key || secrets.ANTHROPIC_API_KEY }}
           allowed_bots: '*'
+          trigger_phrase: '@claude'
           prompt: |
             REPO: ${{ github.repository }}
-            PR NUMBER: ${{ github.event.pull_request.number || github.event.inputs.pr_number }}
+            PR NUMBER: ${{ github.event.pull_request.number || github.event.issue.number || github.event.inputs.pr_number }}
 
             Review this pull request. Only comment on:
             - Bugs or logic errors