diff --git a/.github/workflows/verify-pr.yaml b/.github/workflows/verify-pr.yaml
index 192f4b5..f48a61e 100644
--- a/.github/workflows/verify-pr.yaml
+++ b/.github/workflows/verify-pr.yaml
@@ -36,6 +36,22 @@ jobs:
       - name: Check format
         run: npm run format
 
+  typecheck:
+    name: Typecheck
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout
+        uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1 # v7.0.1
+      - name: Setup Node.js
+        uses: actions/setup-node@820762786026740c76f36085b0efc47a31fe5020 # v7.0.0
+        with:
+          node-version-file: '.nvmrc'
+          cache: npm
+      - name: Install dependencies
+        run: npm ci
+      - name: Check types
+        run: npm run typecheck
+
   build:
     name: Build
     runs-on: ubuntu-latest
diff --git a/agent/runAgentForOnePass.ts b/agent/runAgentForOnePass.ts
index 6542f05..33f0ee6 100644
--- a/agent/runAgentForOnePass.ts
+++ b/agent/runAgentForOnePass.ts
@@ -212,11 +212,15 @@ export async function runAgentForOnePass(
 						hasUnknownPrices: sessionStats.hasUnknownPrices,
 					});
 
+					// `_maxTurns` is `number | null` upstream; null means "unset", in which case we
+					// keep the configured limit rather than clobbering it (a null here would make
+					// the `currentTurn + 1 >= maxTurns` check below fire immediately).
+					const nextMaxTurns = stream.state._maxTurns ?? trackedState.maxTurns;
 					if (
-						trackedState.currentTurn !== stream.state._currentTurn || trackedState.maxTurns !== stream.state._maxTurns
+						trackedState.currentTurn !== stream.state._currentTurn || trackedState.maxTurns !== nextMaxTurns
 					) {
 						trackedState.currentTurn = stream.state._currentTurn;
-						trackedState.maxTurns = stream.state._maxTurns;
+						trackedState.maxTurns = nextMaxTurns;
 						emitToListeners('SettingsUpdated', undefined);
 						if (trackedState.currentTurn + 1 >= trackedState.maxTurns) {
 							await pushNewItemsIntoSession();
@@ -318,7 +322,7 @@ export async function runAgentForOnePass(
 		});
 
 		trackedState.currentTurn = stream.state._currentTurn;
-		trackedState.maxTurns = stream.state._maxTurns;
+		trackedState.maxTurns = stream.state._maxTurns ?? trackedState.maxTurns;
 		emitToListeners('SettingsUpdated', undefined);
 
 		if (stream.interruptions?.length) {
diff --git a/ink/components/BlinkingTextInput.tsx b/ink/components/BlinkingTextInput.tsx
index fc459e7..09d7f2a 100644
--- a/ink/components/BlinkingTextInput.tsx
+++ b/ink/components/BlinkingTextInput.tsx
@@ -182,7 +182,7 @@ export function BlinkingTextInput({
 
 			return (
 				<Box flexGrow={1} minWidth={1}>
-					<Text wrap="end">{displayContent}</Text>
+					<Text wrap="truncate-end">{displayContent}</Text>
 				</Box>
 			);
 		}
@@ -216,7 +216,7 @@ export function BlinkingTextInput({
 
 			result.push(
 				<Box key={lineIndex} flexGrow={1}>
-					<Text wrap="end">{lineContent}</Text>
+					<Text wrap="truncate-end">{lineContent}</Text>
 				</Box>,
 			);
 			if (lineIndex < lines.length - 1) {
diff --git a/ink/configurationWizard/ApiKeyStep.test.tsx b/ink/configurationWizard/ApiKeyStep.test.tsx
index ecb106e..7ffb85c 100644
--- a/ink/configurationWizard/ApiKeyStep.test.tsx
+++ b/ink/configurationWizard/ApiKeyStep.test.tsx
@@ -20,7 +20,9 @@ describe('ApiKeyStep', () => {
 	it('renders API key prompt for OpenAI', () => {
 		const onConfirm = vi.fn();
 		const onBack = vi.fn();
-		const { lastFrame } = render(<ApiKeyStep provider="OpenAI" onConfirm={onConfirm} onBack={onBack} />);
+		const { lastFrame } = render(
+			<ApiKeyStep provider="OpenAI" defaultValue="" onConfirm={onConfirm} onBack={onBack} />,
+		);
 
 		expect(lastFrame()).toContain('Can you provide us with your OpenAI API key?');
 		expect(lastFrame()).toContain('Get your key at: https://platform.openai.com/api-keys');
@@ -29,7 +31,7 @@ describe('ApiKeyStep', () => {
 	it('calls onBack when ESC is pressed', () => {
 		const onConfirm = vi.fn();
 		const onBack = vi.fn();
-		render(<ApiKeyStep provider="OpenAI" onConfirm={onConfirm} onBack={onBack} />);
+		render(<ApiKeyStep provider="OpenAI" defaultValue="" onConfirm={onConfirm} onBack={onBack} />);
 
 		const inputHandler = (useInput as any).mock.calls[0][0];
 		inputHandler('', { escape: true });
diff --git a/ink/configurationWizard/ApiUrlStep.test.tsx b/ink/configurationWizard/ApiUrlStep.test.tsx
index 4684cca..f29c286 100644
--- a/ink/configurationWizard/ApiUrlStep.test.tsx
+++ b/ink/configurationWizard/ApiUrlStep.test.tsx
@@ -20,7 +20,9 @@ describe('ApiUrlStep', () => {
 	it('renders API URL prompt for Ollama', () => {
 		const onConfirm = vi.fn();
 		const onBack = vi.fn();
-		const { lastFrame } = render(<ApiUrlStep provider="Ollama" onConfirm={onConfirm} onBack={onBack} />);
+		const { lastFrame } = render(
+			<ApiUrlStep provider="Ollama" defaultValue="" onConfirm={onConfirm} onBack={onBack} />,
+		);
 
 		expect(lastFrame()).toContain('Where are you hosting Ollama?');
 	});
@@ -28,7 +30,7 @@ describe('ApiUrlStep', () => {
 	it('calls onBack when ESC is pressed', () => {
 		const onConfirm = vi.fn();
 		const onBack = vi.fn();
-		render(<ApiUrlStep provider="Ollama" onConfirm={onConfirm} onBack={onBack} />);
+		render(<ApiUrlStep provider="Ollama" defaultValue="" onConfirm={onConfirm} onBack={onBack} />);
 
 		const inputHandler = (useInput as any).mock.calls[0][0];
 		inputHandler('', { escape: true });
diff --git a/ink/configurationWizard/ModelSelectionStep.test.tsx b/ink/configurationWizard/ModelSelectionStep.test.tsx
index 4cb2dd3..d179234 100644
--- a/ink/configurationWizard/ModelSelectionStep.test.tsx
+++ b/ink/configurationWizard/ModelSelectionStep.test.tsx
@@ -24,6 +24,7 @@ describe('ModelSelectionStep', () => {
 			<ModelSelectionStep
 				title="Pick a model"
 				models={['model-1', 'model-2']}
+				defaultValue=""
 				onConfirm={onConfirm}
 				onBack={onBack}
 			/>,
@@ -42,6 +43,7 @@ describe('ModelSelectionStep', () => {
 			<ModelSelectionStep
 				title="Pick a model"
 				models={['model-1']}
+				defaultValue=""
 				onConfirm={onConfirm}
 				onBack={onBack}
 			/>,
diff --git a/ink/configurationWizard/ProviderStep.test.tsx b/ink/configurationWizard/ProviderStep.test.tsx
index d46c856..d7a5062 100644
--- a/ink/configurationWizard/ProviderStep.test.tsx
+++ b/ink/configurationWizard/ProviderStep.test.tsx
@@ -10,7 +10,8 @@ describe('ProviderStep', () => {
 
 	it('renders provider selection message', () => {
 		const onConfirm = vi.fn();
-		const { lastFrame } = render(<ProviderStep onConfirm={onConfirm} />);
+		const onExit = vi.fn();
+		const { lastFrame } = render(<ProviderStep defaultValue="" onConfirm={onConfirm} onExit={onExit} />);
 
 		expect(lastFrame()).toContain('What model provider would you like to use today?');
 	});
diff --git a/package.json b/package.json
index ab7d734..0ce4bfa 100644
--- a/package.json
+++ b/package.json
@@ -21,6 +21,7 @@
 		"format:fix": "dprint fmt",
 		"format:staged": "dprint check --staged --allow-no-files",
 		"format-and-lint:fix": "npm run format:fix && npm run lint:fix",
+		"typecheck": "tsc --noEmit",
 		"test": "vitest --run",
 		"test:coverage": "vitest run --coverage",
 		"test:watch": "vitest",
diff --git a/tools/browser/browserClickTool.ts b/tools/browser/browserClickTool.ts
index 47b9079..fd7c932 100644
--- a/tools/browser/browserClickTool.ts
+++ b/tools/browser/browserClickTool.ts
@@ -11,7 +11,9 @@ const ToolParameters = z.object({
 export async function execute({ selector, button, clickCount }: z.infer<typeof ToolParameters>) {
 	try {
 		const page = await getPage();
-		await page.click(selector, { button, clickCount });
+		// Puppeteer calls this `count`; passing `clickCount` was silently ignored, so
+		// multi-click requests always performed a single click.
+		await page.click(selector, { button, count: clickCount });
 		return `Successfully clicked on ${selector}`;
 	} catch (error) {
 		return `Error clicking on ${selector}: ${error}`;
diff --git a/tools/files/applyPatchTool.ts b/tools/files/applyPatchTool.ts
index c6e3400..f78c199 100644
--- a/tools/files/applyPatchTool.ts
+++ b/tools/files/applyPatchTool.ts
@@ -31,7 +31,10 @@ async function getSkillsRead(): Promise<string[]> {
 	}
 }
 
-function pickExistingSkill(candidates: string[]): string | null {
+/** The skill names `getHarperSkillTool` actually accepts. */
+type HarperSkillName = (typeof harperSkills)[number];
+
+function pickExistingSkill(candidates: readonly HarperSkillName[]): HarperSkillName | null {
 	for (const c of candidates) { if (harperSkills.includes(c)) { return c; } }
 	return null;
 }
@@ -39,7 +42,7 @@ function pickExistingSkill(candidates: string[]): string | null {
 async function requiredSkillForOperation(
 	path: string,
 	type: 'create_file' | 'update_file' | 'delete_file' | 'overwrite_file',
-): Promise<string | null> {
+): Promise<HarperSkillName | null> {
 	if (type === 'delete_file') { return null; }
 	const p = normalizedPath(path);
 	const read = await getSkillsRead();