feat: show Landing progress with reactions

docs/guides/github.md

@@ -32,6 +32,8 @@ In Actions, Landing supplies the trigger, target, and relevant revisions. The ag
 
 PR review publishes a native [GitHub Review](https://docs.github.com/en/rest/pulls/reviews#create-a-review-for-a-pull-request) for the requested commit, with findings attached to the affected lines. A clean review needs no code comments. Reviews comment by default; approvals and change requests require explicit authorization. The gate recommendation remains separate.
 
+While admitted work runs, Landing adds an eyes reaction to the triggering PR or command comment. When the work finishes, a rocket replaces it for completed work and a confused reaction for failed work; cancelled or superseded runs only remove it. A delegation for a head that is no longer current is rejected before it starts and leaves existing reactions unchanged. A hard-killed runner cannot clean up, so its eyes reaction stays until the next run on that subject replaces it. Reactions are best effort: a token without reaction permission leaves the work and its publication unaffected.
+
 Explicit delegations require a reply to their selected issue or PR; inline follow-ups reply in the original review thread. Landing verifies that the prepared identity published to the requested destination before reporting completion. Include `confirm_reply` when restricting tools for inline follow-ups.
 
 Automatic issuer follow-up publishes only useful new evidence, changed conditions, or verified progress. Unchanged conditions complete quietly through `no_update`, retaining the reason in SQLite. Failed tool execution cannot waive required publication. Explicit questions still require replies.

src/landing/adapters/github.py

@@ -373,6 +373,56 @@ def pull_target(
     return is_pr, thread, head
 
 
+def reaction_endpoint(repository: str, event: dict | None) -> str | None:
+    """Locate the triggering comment or PR, which receives Landing's progress reaction."""
+    comment = (event or {}).get("comment")
+    if comment:
+        kind = "pulls" if "pull_request_review_id" in comment else "issues"
+        return f"repos/{repository}/{kind}/comments/{comment['id']}/reactions" if "id" in comment else None
+    pull = (event or {}).get("pull_request") or {}
+    return f"repos/{repository}/issues/{pull['number']}/reactions" if "number" in pull else None
+
+
+def react(repository: str, endpoint: str, content: str) -> dict | None:
+    # Reactions only signal progress; a missing reaction permission must not fail the delegated work.
+    try:
+        return json.loads(gh(["api", endpoint, "-f", f"content={content}"], repository))
+    except (RuntimeError, subprocess.TimeoutExpired, ValueError) as exc:
+        typer.echo(f"Cannot add the {content} reaction: {exc}", err=True)
+        return None
+
+
+def unreact(repository: str, endpoint: str, reaction: dict) -> None:
+    try:
+        gh(["api", f"{endpoint}/{reaction['id']}", "-X", "DELETE"], repository)
+    except (RuntimeError, subprocess.TimeoutExpired) as exc:
+        typer.echo(f"Cannot remove the {reaction['content']} reaction: {exc}", err=True)
+
+
+def begin_reaction(repository: str, endpoint: str) -> dict | None:
+    progress = react(repository, endpoint, "eyes")
+    if progress is None:
+        return None
+    # A new PR candidate replaces the previous run's outcome, so the PR shows only the latest result.
+    try:
+        reactions = rows(endpoint, repository)
+    except (RuntimeError, subprocess.TimeoutExpired, ValueError) as exc:
+        typer.echo(f"Cannot read earlier reactions: {exc}", err=True)
+        reactions = []
+    for item in reactions:
+        if item.get("user", {}).get("id") == progress["user"]["id"] and item.get("content") in {"rocket", "confused"}:
+            unreact(repository, endpoint, item)
+    return progress
+
+
+def conclude_reaction(repository: str, endpoint: str, progress: dict | None, status: str) -> None:
+    if progress is not None:
+        unreact(repository, endpoint, progress)
+    # A superseded or terminated run leaves no outcome; the next run reports its own.
+    if status != "cancelled":
+        react(repository, endpoint, "rocket" if status == "completed" else "confused")
+
+
 def checkout_contains(workspace: Path, head: str, checked_revision: str) -> bool | None:
     executable = shutil.which("git")
     if not head or not checked_revision or not executable:
@@ -446,6 +496,10 @@ async def run(landing: Runtime, options: GitHubSettings, event: dict | None = No
         checks=options.check if mode in {"fixer", "gatekeeper"} else [],
     )
 
+    # pull_target has already rejected a stale candidate, so its rejection leaves the current outcome in place.
+    endpoint = reaction_endpoint(repository, event)
+    progress = begin_reaction(repository, endpoint) if endpoint else None
+    status = "failed"
     publication = Publication(landing, repository, number, stamp, expected_review, thread, head, reply_required)
     manager = landing.framework.plugin_manager
     manager.register(publication, name="github-publication")
@@ -460,22 +514,31 @@ async def run(landing: Runtime, options: GitHubSettings, event: dict | None = No
                     request.model_copy(update={"input": snapshot}), scope=repository, key=key
                 )
                 publication.verify(action)
-                return landing.tasks.finish(action.id, "completed", result=f"Already published: {existing['html_url']}")
-            try:
-                action = await landing.run(
-                    request,
-                    session_id=f"github:{number or key}",
-                    scope=repository,
-                    key=key,
-                    verify=publication.verify,
+                action = landing.tasks.finish(
+                    action.id, "completed", result=f"Already published: {existing['html_url']}"
                 )
-            except asyncio.CancelledError:
-                if not publication.action_id:
-                    raise
-                action = landing.tasks.get(publication.action_id)
-            return action
+            else:
+                try:
+                    action = await landing.run(
+                        request,
+                        session_id=f"github:{number or key}",
+                        scope=repository,
+                        key=key,
+                        verify=publication.verify,
+                    )
+                except asyncio.CancelledError:
+                    if not publication.action_id:
+                        raise
+                    action = landing.tasks.get(publication.action_id)
+        status = action.status
+    except asyncio.CancelledError:
+        status = "cancelled"
+        raise
     finally:
         manager.unregister(publication)
+        if endpoint:
+            conclude_reaction(repository, endpoint, progress, status)
+    return action
 
 
 def write_outputs(action: Action | None) -> None:

tests/test_github.py

@@ -33,7 +33,21 @@ def platform(tmp_path, monkeypatch):
     raise SystemExit("GitHub is unavailable")
 if args[0] != "api":
     raise SystemExit("Use the native API in this fixture.")
-if "--input" in args:
+reactions = state.setdefault("reactions", {})
+if "/reactions" in endpoint:
+    subject, _, reaction = endpoint.partition("/reactions")
+    if "DELETE" in args:
+        reactions[subject] = [item for item in reactions[subject] if item["id"] != int(reaction.strip("/"))]
+    elif "-f" in args:
+        content = args[args.index("-f") + 1].split("=", 1)[1]
+        state["reaction_id"] = state.get("reaction_id", 0) + 1
+        record = {"id": state["reaction_id"], "content": content, "user": state["publisher"]}
+        reactions.setdefault(subject, []).append(record)
+        print(json.dumps(record))
+    else:
+        print(json.dumps([reactions.get(subject, [])]))
+    path.write_text(json.dumps(state))
+elif "--input" in args:
     source = args[args.index("--input") + 1]
     body = json.loads(sys.stdin.read() if source == "-" else Path(source).read_text())
     kind = "reviews" if endpoint.endswith("/reviews") else "comments"
@@ -234,12 +248,16 @@ def test_agent_publishes_native_review_with_inline_comment_and_deduplicates(plat
     assert published[0]["commit_id"] == "candidate-head"
     assert published[0]["comments"][0]["path"] == "candidate.py"
     assert published[0]["comments"][0]["line"] == 2
+    reactions = json.loads(platform.read_text())["reactions"]
+    assert [item["content"] for item in reactions["repos/example/landing/issues/42"]] == ["rocket"]
     state = json.loads(platform.read_text())
     state["reviews"].append({"id": 9, "body": "A later independent review.", "state": "COMMENTED"})
     platform.write_text(json.dumps(state))
     calls = len(requests)
     assert invoke(event, key="review:42").id == action.id
     assert len(requests) == calls
+    reactions = json.loads(platform.read_text())["reactions"]
+    assert [item["content"] for item in reactions["repos/example/landing/issues/42"]] == ["rocket"]
     assert json.loads(platform.read_text())["reviews"] == state["reviews"]
     monkeypatch.setenv("INPUT_INSTRUCTION", "Review deployment behavior.")
     invoke(event, key="review:42", error="different request")
@@ -371,6 +389,7 @@ async def reply_from_evidence(**kwargs):
     assert len(state["reviews"]) == 2
     assert state["comments"][-1]["in_reply_to_id"] == 17
     assert "initial attempt is unaffected" in state["comments"][-1]["body"]
+    assert [item["content"] for item in state["reactions"]["repos/example/landing/pulls/comments/18"]] == ["rocket"]
     assert invoke(event, key="comment:18").id == action.id
     assert json.loads(platform.read_text())["comments"] == state["comments"]
     event["comment"]["body"] = "Fixed in the latest commit; CI is pending."
@@ -400,9 +419,28 @@ def test_text_without_required_publication_is_failed_work(platform, invoke, mode
     assert action.result == "The review is ready."
     assert action.error is not None
     assert "confirmed publication" in action.error["message"]
+    assert [
+        item["content"] for item in json.loads(platform.read_text())["reactions"]["repos/example/landing/issues/42"]
+    ] == ["confused"]
     assert json.loads(platform.read_text())["reviews"] == state["reviews"]
 
 
+def test_stale_review_delegation_keeps_the_current_outcome_reaction(platform, invoke, model):
+    state = json.loads(platform.read_text())
+    state["head"] = "new-candidate"
+    current = {"repos/example/landing/issues/42": [{"id": 7, "content": "rocket", "user": state["publisher"]}]}
+    state["reactions"] = current
+    platform.write_text(json.dumps(state))
+    event = {
+        "repository": {"full_name": "example/landing"},
+        "sender": {"type": "User", "login": "maintainer"},
+        "pull_request": {"number": 42, "head": {"sha": "candidate-head"}},
+    }
+    invoke(event, key="stale", error="PR head changed")
+    assert json.loads(platform.read_text())["reactions"] == current
+    assert not model[1]
+
+
 @pytest.mark.parametrize("lookup_fails", [False, True])
 def test_review_stops_queued_tools_for_superseded_or_unverifiable_head(tmp_path, platform, invoke, model, lookup_fails):
     responses, requests = model