fix(miner-ui): reset the governor pause reason after a successful pause

GovernorControlSection keeps the pause-reason Input's text in a single `reason`
state for the section's lifetime. The Input is unmounted while paused but the
component instance persists, so after pause→resume the field reappeared
pre-filled with the previous pause's reason — an operator could submit a stale
reason into the persisted governor pause-state.

Reset `reason` to empty the moment a pause succeeds (the polled result flips to
paused), using React's render-phase 'info from previous renders' pattern rather
than an effect. A failed pause leaves result.ok false and never sets paused, so
the typed reason is preserved for a retry. Local-state-only; no callback/route
changes. Adds a pause→resume→pause regression test plus the failed-pause
negative case.

Closes #7079

Author: jaytbarimbao-collab

apps/loopover-miner-ui/src/ledgers.test.tsx

@@ -3,7 +3,7 @@ import { describe, expect, it, vi } from "vitest";
 
 import { fetchLedgers, LEDGERS_API_PATH, type LedgersResult, type LedgersSummary } from "./lib/ledgers";
 import { type GovernorPauseState, type GovernorPauseStateResult } from "./lib/governor";
-import { LedgersPage, LedgersView } from "./routes/ledgers";
+import { GovernorControlSection, LedgersPage, LedgersView } from "./routes/ledgers";
 import { handleLedgersRequest, type LedgersApiDeps } from "../vite-ledgers-api";
 
 // Test-local fixture factories (were lib exports reachable only from tests; moved here per #6187).
@@ -493,3 +493,39 @@ describe("handleLedgersRequest (#4855)", () => {
     expect(handled).toEqual({ status: 500, body: JSON.stringify({ error: "sqlite locked" }) });
   });
 });
+
+describe("GovernorControlSection pause-reason reset (#7079)", () => {
+  const notPaused: GovernorPauseStateResult = { ok: true, pauseState: { paused: false, reason: null, pausedAt: null } };
+  const pausedResult: GovernorPauseStateResult = {
+    ok: true,
+    pauseState: { paused: true, reason: "investigating flaky test", pausedAt: "2026-07-18T00:00:00.000Z" },
+  };
+  const control = (result: GovernorPauseStateResult, onPause = vi.fn()) => (
+    <GovernorControlSection result={result} pending={false} onPause={onPause} onResume={vi.fn()} />
+  );
+
+  it("clears the reason after a successful pause, so a later resume→pause starts from a blank input", () => {
+    const onPause = vi.fn();
+    const { rerender } = render(control(notPaused, onPause));
+    fireEvent.change(screen.getByLabelText("Pause reason"), { target: { value: "investigating flaky test" } });
+    fireEvent.click(screen.getByRole("button", { name: "Pause governor" }));
+    expect(onPause).toHaveBeenCalledWith("investigating flaky test");
+
+    // The poll reflects the successful pause (paused: true), then the operator resumes back to the pause form.
+    rerender(control(pausedResult, onPause));
+    rerender(control(notPaused, onPause));
+    expect((screen.getByLabelText("Pause reason") as HTMLInputElement).value).toBe("");
+  });
+
+  it("preserves the typed reason after a FAILED pause, so it can be retried without retyping", () => {
+    const onPause = vi.fn();
+    const { rerender } = render(control(notPaused, onPause));
+    fireEvent.change(screen.getByLabelText("Pause reason"), { target: { value: "investigating flaky test" } });
+    fireEvent.click(screen.getByRole("button", { name: "Pause governor" }));
+
+    // The pause fails (ok: false): the reset must NOT fire. Re-render back to the form (a retry) and the reason stays.
+    rerender(control({ ok: false, error: "governor state write failed" }, onPause));
+    rerender(control(notPaused, onPause));
+    expect((screen.getByLabelText("Pause reason") as HTMLInputElement).value).toBe("investigating flaky test");
+  });
+});

apps/loopover-miner-ui/src/routes/ledgers.tsx

@@ -336,6 +336,16 @@ export function GovernorControlSection({
   // Optional pause reason, mirroring the CLI's `governor pause [--reason <text>]`; an empty field
   // is passed through as `undefined` so it matches the CLI's own optional-flag behavior.
   const [reason, setReason] = useState("");
+  // #7079: once a pause succeeds the polled `result` flips to paused; clear the reason so a later
+  // resume→pause starts from a blank input. Done with React's "info from previous renders" pattern (a
+  // render-phase reset when `paused` turns true) rather than an effect. A FAILED pause leaves `result.ok`
+  // false and never sets `paused`, so the reason is preserved for a retry.
+  const paused = result?.ok === true && result.pauseState.paused;
+  const [wasPaused, setWasPaused] = useState(paused);
+  if (paused !== wasPaused) {
+    setWasPaused(paused);
+    if (paused) setReason("");
+  }
   const errorText = result !== null && !result.ok ? result.error : undefined;
   return (
     <section className="grid gap-3">