feat: Improve thread resolution with referenced commit context

docs/plugins/generated/github-step-reference.md

@@ -1510,6 +1510,14 @@ Select open inline threads worth AI analysis.
 
 **Available to later steps:** `thread_review_candidates (List[ThreadReviewCandidate])`
 
+**Inputs (from ctx.data)**
+
+| Name | Type | Description |
+|------|------|-------------|
+| review_threads (List[UICommentThread]) | - | - |
+| review_pr (UIPullRequest) | - | - |
+| review_current_user (str) | - | Authenticated GitHub login running Titan |
+
 **Outputs (saved to ctx.data)**
 
 | Name | Type | Description |

docs/plugins/github/client-api.md

@@ -241,6 +241,27 @@ client.get_pr_commit_sha(123)
 
 - `pr_number`: Required. Pull request number.
 
+### Read referenced commit context
+
+Returns compact remote context for a commit SHA mentioned in review discussion,
+including changed files and a truncated patch excerpt suitable for AI prompts.
+
+**Call:**
+
+```python
+client.get_commit_review_context(
+    "343e2e9",
+    max_files=3,
+    max_patch_chars=4000,
+)
+```
+
+**Parameters:**
+
+- `commit_ref`: Required. Full or short commit SHA resolvable in the current repository.
+- `max_files`: Optional. Maximum number of changed files to include in the returned context.
+- `max_patch_chars`: Optional. Maximum combined patch excerpt size before truncation.
+
 ### Merge a pull request
 
 Merges a pull request using the selected merge strategy.

docs/plugins/github/workflow-steps.md

@@ -388,7 +388,11 @@ How to read these contracts:
 
     **Inputs (from ctx.data)**
 
-    None documented.
+    | Name | Type | Description |
+    |------|------|-------------|
+    | review_threads (List[UICommentThread]) | - | - |
+    | review_pr (UIPullRequest) | - | - |
+    | review_current_user (str) | - | Authenticated GitHub login running Titan |
 
     **Outputs (saved to ctx.data)**
 

plugins/titan-plugin-github/tests/operations/test_thread_resolution_operations.py

@@ -0,0 +1,87 @@
+from titan_plugin_github.models.review_models import ReferencedCommitContext, ThreadReviewContext
+from titan_plugin_github.models.view import UIComment, UICommentThread
+from titan_plugin_github.operations.thread_resolution_operations import (
+    build_thread_resolution_prompt,
+    build_thread_review_candidates,
+)
+
+
+def _make_thread(*, main_author: str, reply_author: str) -> UICommentThread:
+    return UICommentThread(
+        thread_id=f"thread_{main_author}_{reply_author}",
+        main_comment=UIComment(
+            id=10,
+            body="Please fix this",
+            author_login=main_author,
+            author_name=main_author,
+            formatted_date="",
+            path="src/main.py",
+            line=42,
+        ),
+        replies=[
+            UIComment(
+                id=11,
+                body="Fixed",
+                author_login=reply_author,
+                author_name=reply_author,
+                formatted_date="",
+                path="src/main.py",
+                line=42,
+            )
+        ],
+        is_resolved=False,
+        is_outdated=False,
+    )
+
+
+def test_build_thread_review_candidates_only_includes_current_users_threads():
+    candidates = build_thread_review_candidates(
+        [
+            _make_thread(main_author="current-reviewer", reply_author="pr-author"),
+            _make_thread(main_author="other-reviewer", reply_author="pr-author"),
+        ],
+        pr_author="pr-author",
+        reviewer_login="current-reviewer",
+    )
+
+    assert len(candidates) == 1
+    assert candidates[0].main_comment_author == "current-reviewer"
+
+
+def test_build_thread_review_candidates_excludes_threads_without_pr_author_last_reply():
+    candidates = build_thread_review_candidates(
+        [_make_thread(main_author="current-reviewer", reply_author="other-reviewer")],
+        pr_author="pr-author",
+        reviewer_login="current-reviewer",
+    )
+
+    assert candidates == []
+
+
+def test_build_thread_resolution_prompt_includes_referenced_commit_context():
+    context = ThreadReviewContext(
+        thread_id="thread_123",
+        comment_id=10,
+        path="src/buttons.kt",
+        line=543,
+        main_comment_body="Please remove the default dialog state.",
+        main_comment_author="reviewer",
+        all_replies=[{"author": "author", "body": "Fixed in 343e2e9"}],
+        current_code_hunk="@@ -1,2 +1,2 @@\n-old\n+new\n",
+        referenced_commits=[
+            ReferencedCommitContext(
+                sha="343e2e9d7402d0afccfd35a9ecc8e6ea341031c6",
+                abbreviated_sha="343e2e9",
+                message="remove default state value",
+                changed_files=["src/BaseDialog.kt"],
+                patch_excerpt="diff --git a/src/BaseDialog.kt b/src/BaseDialog.kt\n@@ -1 +1 @@\n-old\n+new\n",
+            )
+        ],
+    )
+
+    prompt = build_thread_resolution_prompt([context])
+
+    assert "Referenced commits from replies" in prompt
+    assert "343e2e9" in prompt
+    assert "src/BaseDialog.kt" in prompt
+    assert "remove default state value" in prompt

plugins/titan-plugin-github/tests/services/test_pr_service.py

@@ -190,3 +190,67 @@ def test_merge_pr_failure(pr_service, mock_gh_network):
     assert result.data.merged is False
     assert result.data.status_icon == "❌"
     assert "not mergeable" in result.data.message.lower()
+
+
+def test_get_commit_review_context_success(pr_service, mock_gh_network):
+    """Test commit context retrieval for a referenced SHA."""
+    mock_gh_network.run_command.return_value = json.dumps(
+        {
+            "sha": "343e2e9d7402d0afccfd35a9ecc8e6ea341031c6",
+            "commit": {"message": "remove default state value"},
+            "files": [
+                {
+                    "filename": "freyja-core/src/main/kotlin/.../BaseDialog.kt",
+                    "status": "modified",
+                    "patch": "@@ -36,7 +35,7 @@\n-fun BaseDialog(dialogState: DialogState = remember { DialogState() })\n+fun BaseDialog(dialogState: DialogState)\n",
+                }
+            ],
+        }
+    )
+
+    result = pr_service.get_commit_review_context("343e2e9")
+
+    assert isinstance(result, ClientSuccess)
+    assert result.data.abbreviated_sha == "343e2e9"
+    assert result.data.changed_files == ["freyja-core/src/main/kotlin/.../BaseDialog.kt"]
+    assert "remove default state value" == result.data.message
+    assert "diff --git a/freyja-core/src/main/kotlin/.../BaseDialog.kt" in result.data.patch_excerpt
+    assert "repos/test-owner/test-repo/commits/343e2e9" in mock_gh_network.run_command.call_args[0][0][1]
+
+
+def test_get_commit_review_context_uses_head_repo_when_provided(pr_service, mock_gh_network):
+    """Test that repo_owner/repo_name override the configured base repo (fork PRs)."""
+    mock_gh_network.run_command.return_value = json.dumps(
+        {
+            "sha": "343e2e9d7402d0afccfd35a9ecc8e6ea341031c6",
+            "commit": {"message": "remove default state value"},
+            "files": [],
+        }
+    )
+
+    result = pr_service.get_commit_review_context(
+        "343e2e9", repo_owner="fork-owner", repo_name="fork-repo"
+    )
+
+    assert isinstance(result, ClientSuccess)
+    assert "repos/fork-owner/fork-repo/commits/343e2e9" in mock_gh_network.run_command.call_args[0][0][1]
+
+
+def test_get_commit_review_context_returns_parse_error_on_invalid_json(pr_service, mock_gh_network):
+    """Test invalid commit payload handling."""
+    mock_gh_network.run_command.return_value = "not json"
+
+    result = pr_service.get_commit_review_context("343e2e9")
+
+    assert isinstance(result, ClientError)
+    assert result.error_code == "PARSE_ERROR"
+
+
+def test_get_commit_review_context_returns_api_error_on_network_failure(pr_service, mock_gh_network):
+    """Test GitHub API failure handling."""
+    mock_gh_network.run_command.side_effect = GitHubAPIError("Not Found")
+
+    result = pr_service.get_commit_review_context("343e2e9")
+
+    assert isinstance(result, ClientError)
+    assert result.error_code == "API_ERROR"