diff --git a/biome.json b/biome.json
index 65f23abcb..33207c298 100644
--- a/biome.json
+++ b/biome.json
@@ -1,5 +1,5 @@
 {
-	"$schema": "https://biomejs.dev/schemas/2.4.14/schema.json",
+	"$schema": "https://biomejs.dev/schemas/2.4.15/schema.json",
 	"vcs": {
 		"enabled": true,
 		"clientKind": "git",
diff --git a/packages/coding-agent/src/core/subagent-runner.ts b/packages/coding-agent/src/core/subagent-runner.ts
index 42a496346..e1127555c 100644
--- a/packages/coding-agent/src/core/subagent-runner.ts
+++ b/packages/coding-agent/src/core/subagent-runner.ts
@@ -327,7 +327,14 @@ export async function runSubagent(
 		`[subagent:${name}] phase=session.prompt-entered taskLen=${promptTask.length} timeoutMs=${timeoutMs} noOutputMs=${noOutputTimeoutMs}\n`,
 	);
 	const promptEnteredAt = phaseStartedAt();
-	const promptWatchdog = phaseWatchdog("session.prompt", promptEnteredAt);
+	// Note: no phaseWatchdog for session.prompt. The 10s STUCK warning fired
+	// spuriously on healthy 30–60s LLM responses (verified by strace: bytes
+	// were flowing on the TLS socket the whole time). The noOutputTimeoutMs
+	// watchdog below is the event-aware replacement — it resets on every
+	// meaningful subagent event (see armNoOutputTimer / isMeaningfulSubagent-
+	// OutputEvent) and aborts only after a true silence window. Keep the
+	// STUCK watchdog for setup phases (resourceLoader.reload, createAgent-
+	// Session, bindExtensions) where 10s of silence really is a hang signal.
 
 	try {
 		if (timeoutMs === 0 && noOutputTimeoutMs === 0 && !options?.signal) {
@@ -336,7 +343,6 @@ export async function runSubagent(
 				runExtensionHooks: false,
 			});
 			await promptPromise;
-			clearTimeout(promptWatchdog);
 			logPhase("session.prompt-returned", promptEnteredAt);
 			cleanup();
 			return { ok: true, output: extractFinalOutput(), exitCode: 0 };
@@ -416,7 +422,6 @@ export async function runSubagent(
 		});
 		competitors.unshift(
 			promptPromise.then(() => {
-				clearTimeout(promptWatchdog);
 				logPhase("session.prompt-returned", promptEnteredAt);
 				return {} as RaceResult;
 			}),
@@ -425,7 +430,6 @@ export async function runSubagent(
 		const result = await Promise.race(competitors);
 
 		cleanup();
-		clearTimeout(promptWatchdog);
 
 		if (result.timedOut) {
 			return {
diff --git a/scripts/check-test-imports.mjs b/scripts/check-test-imports.mjs
index f65cd8870..c8ea932c9 100644
--- a/scripts/check-test-imports.mjs
+++ b/scripts/check-test-imports.mjs
@@ -30,54 +30,207 @@ const root = resolve(__dirname, "..");
 // ── Helpers ───────────────────────────────────────────────────────────────────
 
 const NODE_BUILTINS = new Set([
-	"process", "require", "module", "exports", "console", "global", "Buffer",
-	"setTimeout", "setInterval", "clearTimeout", "clearInterval", "queueMicrotask",
-	"Array", "Object", "String", "Number", "Boolean", "Symbol", "BigInt",
-	"Map", "Set", "WeakMap", "WeakSet", "Promise", "Math", "JSON", "Date",
-	"RegExp", "Error", "EvalError", "RangeError", "ReferenceError", "SyntaxError",
-	"TypeError", "URIError", "AggregateError", "AbortController", "AbortSignal",
-	"URL", "URLSearchParams", "TextEncoder", "TextDecoder", "TransformStream",
-	"ReadableStream", "WritableStream", "Blob", "File", "FormData", "Headers",
-	"Request", "Response", "fetch", "WebSocket", "EventSource",
-	"setImmediate", "clearImmediate", "structuredClone", "atob", "btoa",
-	"navigator", "window", "document", "location", "history", "gc",
-	"finalizationRegistry", "Intl", "Reflect", "Proxy",
+	"process",
+	"require",
+	"module",
+	"exports",
+	"console",
+	"global",
+	"Buffer",
+	"setTimeout",
+	"setInterval",
+	"clearTimeout",
+	"clearInterval",
+	"queueMicrotask",
+	"Array",
+	"Object",
+	"String",
+	"Number",
+	"Boolean",
+	"Symbol",
+	"BigInt",
+	"Map",
+	"Set",
+	"WeakMap",
+	"WeakSet",
+	"Promise",
+	"Math",
+	"JSON",
+	"Date",
+	"RegExp",
+	"Error",
+	"EvalError",
+	"RangeError",
+	"ReferenceError",
+	"SyntaxError",
+	"TypeError",
+	"URIError",
+	"AggregateError",
+	"AbortController",
+	"AbortSignal",
+	"URL",
+	"URLSearchParams",
+	"TextEncoder",
+	"TextDecoder",
+	"TransformStream",
+	"ReadableStream",
+	"WritableStream",
+	"Blob",
+	"File",
+	"FormData",
+	"Headers",
+	"Request",
+	"Response",
+	"fetch",
+	"WebSocket",
+	"EventSource",
+	"setImmediate",
+	"clearImmediate",
+	"structuredClone",
+	"atob",
+	"btoa",
+	"navigator",
+	"window",
+	"document",
+	"location",
+	"history",
+	"gc",
+	"finalizationRegistry",
+	"Intl",
+	"Reflect",
+	"Proxy",
 	// Node.js globals (not ESM builtins but always available)
-	"__dirname", "__filename", "import", "imports",
+	"__dirname",
+	"__filename",
+	"import",
+	"imports",
 ]);
 
 // Node.js module exports commonly used in tests without explicit import
 const NODE_MODULE_GLOBALS = new Set([
-	"assert", "assertEq", "deepEqual", "strictEqual",
-	"path", "fs", "os", "url", "querystring", "crypto", "buffer",
-	"stream", "util", "events", "querystring", "stringDecoder",
-	"readline", "tty", "domain", "constants", " timers", "async_hooks",
+	"assert",
+	"assertEq",
+	"deepEqual",
+	"strictEqual",
+	"path",
+	"fs",
+	"os",
+	"url",
+	"querystring",
+	"crypto",
+	"buffer",
+	"stream",
+	"util",
+	"events",
+	"querystring",
+	"stringDecoder",
+	"readline",
+	"tty",
+	"domain",
+	"constants",
+	" timers",
+	"async_hooks",
 ]);
 
 // JavaScript reserved words and keywords that should never be flagged as undeclared
 const JS_KEYWORDS = new Set([
 	// Reserved words
-	"break", "case", "catch", "continue", "debugger", "default", "delete",
-	"do", "else", "finally", "for", "function", "if", "in", "instanceof",
-	"new", "return", "switch", "this", "throw", "try", "typeof", "var",
-	"void", "while", "with", "class", "const", "enum", "export", "extends",
-	"import", "super", "implements", "interface", "let", "package", "private",
-	"protected", "public", "static", "yield", "async", "await", "of",
-	"get", "set", "target", "from", "as",
+	"break",
+	"case",
+	"catch",
+	"continue",
+	"debugger",
+	"default",
+	"delete",
+	"do",
+	"else",
+	"finally",
+	"for",
+	"function",
+	"if",
+	"in",
+	"instanceof",
+	"new",
+	"return",
+	"switch",
+	"this",
+	"throw",
+	"try",
+	"typeof",
+	"var",
+	"void",
+	"while",
+	"with",
+	"class",
+	"const",
+	"enum",
+	"export",
+	"extends",
+	"import",
+	"super",
+	"implements",
+	"interface",
+	"let",
+	"package",
+	"private",
+	"protected",
+	"public",
+	"static",
+	"yield",
+	"async",
+	"await",
+	"of",
+	"get",
+	"set",
+	"target",
+	"from",
+	"as",
 ]);
 
 // Common test framework globals that are always available in vitest/jest
 const TEST_GLOBALS = new Set([
-	"describe", "it", "test", "expect", "beforeEach", "afterEach",
-	"beforeAll", "afterAll", "suite", "spec", "context", "given",
-	"when", "then", "and", "describe.skip", "it.skip", "test.skip",
-	"describe.only", "it.only", "test.only", "describe.each", "it.each",
-	"test.each", "describe.concurrent", "it.concurrent", "test.concurrent",
-	"vi", "vitest", "spyOn", "jest",
+	"describe",
+	"it",
+	"test",
+	"expect",
+	"beforeEach",
+	"afterEach",
+	"beforeAll",
+	"afterAll",
+	"suite",
+	"spec",
+	"context",
+	"given",
+	"when",
+	"then",
+	"and",
+	"describe.skip",
+	"it.skip",
+	"test.skip",
+	"describe.only",
+	"it.only",
+	"test.only",
+	"describe.each",
+	"it.each",
+	"test.each",
+	"describe.concurrent",
+	"it.concurrent",
+	"test.concurrent",
+	"vi",
+	"vitest",
+	"spyOn",
+	"jest",
 ]);
 
 // Boolean and literal values that always exist
-const JS_LITERALS = new Set(["true", "false", "null", "undefined", "NaN", "Infinity"]);
+const JS_LITERALS = new Set([
+	"true",
+	"false",
+	"null",
+	"undefined",
+	"NaN",
+	"Infinity",
+]);
 
 /**
  * Parse the statically-imported identifiers from the top of a file.
@@ -92,7 +245,7 @@ function parseImports(source) {
 	const stripped = source
 		.replace(/'[^']*'/g, "'_'")
 		.replace(/"[^"]*"/g, '"_"')
-		.replace(/`[^`]*`/g, '``_`')
+		.replace(/`[^`]*`/g, "``_`")
 		.replace(/\/\/[^\n]*/g, "")
 		.replace(/\/\*[\s\S]*?\*\//g, "");
 
@@ -107,16 +260,19 @@ function parseImports(source) {
 	const namedRe = /import\s+\{([^}]+)\}\s+from\s+["'][^"']+["']/g;
 	for (const m of stripped.matchAll(namedRe)) {
 		const content = m[1];
-		const items = content.split(",").map((s) => {
-			s = s.trim();
-			if (s.includes(" as ")) {
-				s = s.split(" as ").pop().trim();
-			}
-			if (s.startsWith("type ")) {
-				s = s.replace("type ", "").trim();
-			}
-			return s.replace(/\s+/g, "");
-		}).filter(Boolean);
+		const items = content
+			.split(",")
+			.map((s) => {
+				s = s.trim();
+				if (s.includes(" as ")) {
+					s = s.split(" as ").pop().trim();
+				}
+				if (s.startsWith("type ")) {
+					s = s.replace("type ", "").trim();
+				}
+				return s.replace(/\s+/g, "");
+			})
+			.filter(Boolean);
 		items.forEach((id) => named.add(id));
 	}
 
@@ -143,7 +299,7 @@ function collectReferences(source) {
 	const stripped = source
 		.replace(/'[^']*'/g, "'_'")
 		.replace(/"[^"]*"/g, '"_"')
-		.replace(/`[^`]*`/g, '``_`')
+		.replace(/`[^`]*`/g, "``_`")
 		.replace(/\/\/[^\n]*/g, "")
 		.replace(/\/\*[\s\S]*?\*\//g, "");
 
@@ -154,7 +310,7 @@ function collectReferences(source) {
 
 	// Replace member expressions and calls with placeholders to isolate identifiers
 	const cleaned = stripped
-		.replace(/\b[a-zA-Z_$][\w$]*\.[a-zA-Z_$][\w$]*(?=\s*[\[.\(])/g, "_")
+		.replace(/\b[a-zA-Z_$][\w$]*\.[a-zA-Z_$][\w$]*(?=\s*[[.(])/g, "_")
 		.replace(/\[[^\]]+\]/g, "[_]");
 
 	// Now collect bare identifiers (word boundaries)
@@ -208,13 +364,22 @@ function checkFile(filePath, source) {
 	// - Variable names assigned in try/catch or before import
 	// - Playwright/MCP test helpers
 	const COMMON_TEST_LOCALS = new Set([
-		"canLaunchChromium", "isAvailable", "hasSupport", "isSupported",
-		"describeOrSkip", "itOrSkip", "skipIf", "runIf",
-		"jiti", "interopDefault", "debug",
+		"canLaunchChromium",
+		"isAvailable",
+		"hasSupport",
+		"isSupported",
+		"describeOrSkip",
+		"itOrSkip",
+		"skipIf",
+		"runIf",
+		"jiti",
+		"interopDefault",
+		"debug",
 	]);
 
 	const filteredUndeclared = [...undeclared].filter(
-		(id) => !COMMON_TEST_LOCALS.has(id) &&
+		(id) =>
+			!COMMON_TEST_LOCALS.has(id) &&
 			!id.match(/^(can|has|is|should|will)[A-Z]/) &&
 			!id.match(/^(testBrowser|chromiumInstance|pageInstance)$/),
 	);
@@ -251,9 +416,12 @@ function findTestFiles(dir) {
 				}
 				results.push(...findTestFiles(full));
 			} else if (
-				(entry.name.endsWith(".test.js") || entry.name.endsWith(".test.mjs") ||
-				 entry.name.endsWith(".test.ts") || entry.name.endsWith(".spec.js") ||
-				 entry.name.endsWith(".spec.mjs") || entry.name.endsWith(".spec.ts")) &&
+				(entry.name.endsWith(".test.js") ||
+					entry.name.endsWith(".test.mjs") ||
+					entry.name.endsWith(".test.ts") ||
+					entry.name.endsWith(".spec.js") ||
+					entry.name.endsWith(".spec.mjs") ||
+					entry.name.endsWith(".spec.ts")) &&
 				!entry.name.includes("node_modules")
 			) {
 				results.push(full);
@@ -271,9 +439,7 @@ const verbose = args.includes("--verbose");
 
 // If specific paths are provided, use those instead of scanning
 // Filter out only flag args, keep everything else as a file path
-const explicitPaths = args.filter(
-	(a) => !a.startsWith("--"),
-);
+const explicitPaths = args.filter((a) => !a.startsWith("--"));
 
 let allFiles = [];
 if (explicitPaths.length > 0) {
@@ -293,7 +459,9 @@ if (explicitPaths.length > 0) {
 		process.exit(1);
 	}
 	if (verbose) {
-		console.error(`[check-test-imports] explicit mode: ${allFiles.length} file(s)`);
+		console.error(
+			`[check-test-imports] explicit mode: ${allFiles.length} file(s)`,
+		);
 	}
 } else {
 	const scanDirs = [
@@ -341,4 +509,4 @@ if (jsonOut) {
 	}
 }
 
-process.exit(issues.length > 0 ? 1 : 0);
\ No newline at end of file
+process.exit(issues.length > 0 ? 1 : 0);
diff --git a/scripts/check-test-imports.test.mjs b/scripts/check-test-imports.test.mjs
index ba785fb55..7f96095c6 100644
--- a/scripts/check-test-imports.test.mjs
+++ b/scripts/check-test-imports.test.mjs
@@ -42,14 +42,22 @@ function run(args) {
 
 /** Create a temp test file, return absolute path. */
 function makeTempFile(id, content) {
-	try { mkdirSync(tmpDir, { recursive: true }); } catch { /* */ }
+	try {
+		mkdirSync(tmpDir, { recursive: true });
+	} catch {
+		/* */
+	}
 	const file = resolve(tmpDir, `regression-${id}.test.mjs`);
 	writeFileSync(file, content);
 	return file;
 }
 
 function cleanupTempDir() {
-	try { rmdirSync(tmpDir); } catch { /* ignore */ }
+	try {
+		rmdirSync(tmpDir);
+	} catch {
+		/* ignore */
+	}
 }
 
 // ── Tests ─────────────────────────────────────────────────────────────────────
@@ -89,7 +97,9 @@ if (!existsSync(realFile)) {
 
 // ── Test 2: Detects undeclared identifier in anti-pattern file ───────────────
 console.log("\n[2] Detects undeclared identifier in anti-pattern file");
-const file2 = makeTempFile("regression-02", `
+const file2 = makeTempFile(
+	"regression-02",
+	`
 // Regression test — generated by check-test-imports.test.mjs
 // DO NOT COMMIT
 import { describe, it, expect } from "vitest";
@@ -100,7 +110,8 @@ describe("test", () => {
 		undeclaredFn();
 	});
 });
-`);
+`,
+);
 const result2 = run([file2, "--json"]);
 try {
 	const parsed = JSON.parse(result2.stdout);
@@ -118,7 +129,9 @@ try {
 
 // ── Test 3: Clean file with namespace import passes ─────────────────────────
 console.log("\n[3] Clean file with namespace import + local vars passes");
-const file3 = makeTempFile("regression-03", `
+const file3 = makeTempFile(
+	"regression-03",
+	`
 // Clean: namespace import + only local variables
 // DO NOT COMMIT
 import { describe, it, expect } from "vitest";
@@ -131,21 +144,21 @@ describe("test", () => {
 		expect(myLocalVar).toBeDefined();
 	});
 });
-`);
+`,
+);
 const result3 = run([file3, "--json"]);
 try {
 	const parsed = JSON.parse(result3.stdout);
-	assert(
-		parsed.count === 0,
-		`Clean file: count ${parsed.count}`,
-	);
+	assert(parsed.count === 0, `Clean file: count ${parsed.count}`);
 } catch {
 	assert(false, `Script should not throw on clean file`);
 }
 
 // ── Test 4: Local const/let declarations not flagged ───────────────────────
 console.log("\n[4] Local const/let declarations not flagged");
-const file4 = makeTempFile("regression-04", `
+const file4 = makeTempFile(
+	"regression-04",
+	`
 // Local variable declarations should not be flagged
 // DO NOT COMMIT
 import { describe, it, expect } from "vitest";
@@ -159,7 +172,8 @@ describe("test", () => {
 		expect(myLocalVar).toBeDefined();
 	});
 });
-`);
+`,
+);
 const result4 = run([file4, "--json"]);
 try {
 	const parsed = JSON.parse(result4.stdout);
@@ -173,7 +187,9 @@ try {
 
 // ── Test 5: Short lowercase variables not flagged ───────────────────────────
 console.log("\n[5] Short lowercase variables not flagged");
-const file5 = makeTempFile("regression-05", `
+const file5 = makeTempFile(
+	"regression-05",
+	`
 // Short lowercase vars like i, fn are common test locals
 // DO NOT COMMIT
 import { describe, it, expect } from "vitest";
@@ -186,7 +202,8 @@ describe("test", () => {
 		expect(j).toBeGreaterThan(0);
 	});
 });
-`);
+`,
+);
 const result5 = run([file5, "--json"]);
 try {
 	const parsed = JSON.parse(result5.stdout);
@@ -203,4 +220,4 @@ try {
 console.log(`\n${"-".repeat(50)}`);
 console.log(`Results: ${passed} passed, ${failed} failed`);
 cleanupTempDir();
-process.exit(failed > 0 ? 1 : 0);
\ No newline at end of file
+process.exit(failed > 0 ? 1 : 0);