feat(tui): cycle reasoning tiers with Tab key (#1019)

Co-authored-by: paulbettner <paulbettner@playfulstudios.com>

src/tests/cli/reasoning-cycle-wiring.test.ts

@@ -0,0 +1,48 @@
+import { describe, expect, test } from "bun:test";
+import { readFileSync } from "node:fs";
+import { fileURLToPath } from "node:url";
+
+describe("reasoning tier cycle wiring", () => {
+  test("resets pending reasoning-cycle state across context/model switches", () => {
+    const appPath = fileURLToPath(
+      new URL("../../cli/App.tsx", import.meta.url),
+    );
+    const source = readFileSync(appPath, "utf-8");
+
+    expect(source).toContain(
+      "const resetPendingReasoningCycle = useCallback(() => {",
+    );
+    expect(source).toContain("reasoningCycleDesiredRef.current = null;");
+    expect(source).toContain("reasoningCycleLastConfirmedRef.current = null;");
+
+    const resetCalls = source.match(/resetPendingReasoningCycle\(\);/g) ?? [];
+    expect(resetCalls.length).toBeGreaterThanOrEqual(4);
+
+    expect(source).toContain(
+      "// Drop any pending reasoning-tier debounce before switching contexts.",
+    );
+    expect(source).toContain(
+      "// New conversations should not inherit pending reasoning-tier debounce.",
+    );
+    expect(source).toContain(
+      "// Clearing conversation state should also clear pending reasoning-tier debounce.",
+    );
+    expect(source).toContain(
+      "// Switching models should discard any pending debounce from the previous model.",
+    );
+  });
+
+  test("timer callbacks clear timer ref before re-flushing", () => {
+    const appPath = fileURLToPath(
+      new URL("../../cli/App.tsx", import.meta.url),
+    );
+    const source = readFileSync(appPath, "utf-8");
+
+    const callbackBlocks =
+      source.match(
+        /reasoningCycleTimerRef\.current = setTimeout\(\(\) => \{\n {8}reasoningCycleTimerRef\.current = null;\n {8}void flushPendingReasoningEffort\(\);\n {6}\}, reasoningCycleDebounceMs\);/g,
+      ) ?? [];
+
+    expect(callbackBlocks.length).toBeGreaterThanOrEqual(2);
+  });
+});