fix(notifications): enrich disposition notifications with the gate verdict

src/services/agent-action-executor.ts

@@ -38,6 +38,7 @@ import {
 } from "../settings/moderation-rules";
 import { incr } from "../selfhost/metrics";
 import { shouldWaitForOlderSiblings } from "../review/merge-train";
+import { resolveDispositionReason } from "../review/outcomes-wire";
 import { captureError } from "../selfhost/sentry";
 
 // The agent actor name on every audit record — the App acts on the maintainer's behalf per their configured
@@ -555,7 +556,12 @@ export async function executeAgentMaintenanceActions(env: Env, ctx: AgentActionE
       const notifyOutcome: NotifyOutcome | null =
         action.actionClass === "merge" ? "merged" : action.actionClass === "close" ? "closed" : action.actionClass === "request_changes" ? "manual" : null;
       if (notifyOutcome) {
-        const notifyParams = { repoFullName: ctx.repoFullName, pullNumber: ctx.pullNumber, outcome: notifyOutcome, summary: action.reason, submitter: ctx.authorLogin };
+        // #6636: surface the AI's actual gate reasoning — the reasonCode summary on the most recent gate_decision
+        // row for this PR — as the notification reason, falling back to the plain disposition reason when no
+        // verdict is on record or the read fails. This is the live consumer resolveDispositionReason was built for
+        // (its own doc comment promises the "enriched, verdict-aware reason the user actually sees").
+        const dispositionReason = await resolveDispositionReason(env, targetKey, action.reason);
+        const notifyParams = { repoFullName: ctx.repoFullName, pullNumber: ctx.pullNumber, outcome: notifyOutcome, summary: dispositionReason, submitter: ctx.authorLogin };
         await notifyActionToDiscord(env, notifyParams).catch(() => undefined);
         await notifyActionToSlack(env, notifyParams).catch(() => undefined);
       }

test/unit/agent-action-executor.test.ts

@@ -48,13 +48,19 @@ vi.mock("../../src/github/backfill", async (importOriginal) => ({
   fetchLivePullRequestState: vi.fn(async () => "open" as const),
   refreshInstallationHealthForInstallation: vi.fn(async () => null),
 }));
+vi.mock("../../src/services/notify-discord", async (importOriginal) => ({
+  ...(await importOriginal<typeof import("../../src/services/notify-discord")>()),
+  notifyActionToDiscord: vi.fn(async () => undefined),
+  notifyActionToSlack: vi.fn(async () => undefined),
+}));
 
 import { closeIssue, closePullRequest, createIssueComment, createPullRequestReview, dismissLatestBotApproval, mergePullRequest, updatePullRequestBranch } from "../../src/github/pr-actions";
 import { ensurePullRequestLabel, removePullRequestLabel } from "../../src/github/labels";
 import { ensurePullRequestAssignee } from "../../src/github/assignees";
 import { fetchPullRequestFreshness } from "../../src/github/pr-freshness";
 import { createInstallationToken } from "../../src/github/app";
 import { fetchLiveCiAggregate, fetchLivePullRequestMergeState, fetchLivePullRequestState, fetchLiveReviewThreadBlockers, refreshInstallationHealthForInstallation } from "../../src/github/backfill";
+import { notifyActionToDiscord, notifyActionToSlack } from "../../src/services/notify-discord";
 import {
   actionParams,
   applyModerationEscalationForRule,
@@ -417,6 +423,31 @@ describe("executeAgentMaintenanceActions (#778 gate stack)", () => {
     expect(mergePullRequest).toHaveBeenCalled();
   });
 
+  it("#6636: a terminal disposition notification uses the recorded gate verdict as its reason when one is on record", async () => {
+    const env = createTestEnv({});
+    // The latest gate_decision row for this PR carries the AI's reasoning — the enriched reason resolveDispositionReason surfaces.
+    await env.DB.prepare(
+      "INSERT INTO review_audit (id, project, target_id, event_type, decision, source, head_sha, summary, created_at) VALUES (?,?,?,?,?,?,?,?,?)",
+    )
+      .bind("gate:owner/repo#7", "owner/repo", "owner/repo#7", "gate_decision", "close", "gittensory-native", "sha7", "An AI reviewer flagged a likely blocking defect", "2026-06-21T00:00:00.000Z")
+      .run();
+
+    const outcomes = await executeAgentMaintenanceActions(env, ctx(), [merge]);
+    expect(outcomes[0]?.outcome).toBe("completed");
+    expect(mergePullRequest).toHaveBeenCalled();
+    // The rendered notification shows the gate verdict, NOT the plain disposition reason ("clean").
+    expect(notifyActionToDiscord).toHaveBeenCalledWith(env, expect.objectContaining({ outcome: "merged", summary: "An AI reviewer flagged a likely blocking defect" }));
+    expect(notifyActionToSlack).toHaveBeenCalledWith(env, expect.objectContaining({ outcome: "merged", summary: "An AI reviewer flagged a likely blocking defect" }));
+  });
+
+  it("#6636: the disposition notification falls back to the plain disposition reason when no gate verdict is on record", async () => {
+    const env = createTestEnv({});
+    const outcomes = await executeAgentMaintenanceActions(env, ctx(), [merge]);
+    expect(outcomes[0]?.outcome).toBe("completed");
+    expect(notifyActionToDiscord).toHaveBeenCalledWith(env, expect.objectContaining({ outcome: "merged", summary: merge.reason }));
+    expect(notifyActionToSlack).toHaveBeenCalledWith(env, expect.objectContaining({ outcome: "merged", summary: merge.reason }));
+  });
+
   it("honors a CUSTOM configured manualReviewLabel name (case-insensitive) instead of only the literal default", async () => {
     const env = createTestEnv({});
     vi.mocked(fetchPullRequestFreshness).mockResolvedValueOnce({ status: "current", liveHeadSha: "sha7", liveState: "open", liveLabels: ["Needs-Human"] });