refactor(util): strip comment noise

Removes file-header banners and comments that restate the code. Keeps
one-line notes at the optional-sharp dynamic import, the sharp .default
probe, the `never` contravariance trick, the sanctioned renderCall cast,
and safeJs's interpolation rule.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

4 files changed, 5 insertions, 42 deletions

diff --git a/src/util/js-template.ts b/src/util/js-template.ts
index 392dbc0..75e0217 100644
--- a/src/util/js-template.ts
+++ b/src/util/js-template.ts
@@ -1,19 +1,4 @@
-/**
- * Build a JavaScript source string with safely-interpolated values.
- * Every interpolated value is JSON.stringify'd, so strings, numbers,
- * objects, and special characters all become valid JS literals.
- *
- * This is the ONLY supported way to interpolate untrusted values into
- * evaluation source — never use raw template literals for JS that
- * crosses the CDP boundary. The static parts of the template (the
- * `strings` array) must remain hard-coded; only the `${...}` slots
- * are sanitized.
- *
- * Values must be JSON-serializable: BigInt and Symbol throw at runtime;
- * functions and undefined serialize to `undefined`/omitted, which yields
- * a ReferenceError when evaluated. Pass strings, numbers, booleans,
- * plain objects, or arrays.
- */
+// The ONLY supported way to interpolate untrusted values into evaluation source — never use raw template literals for JS crossing the CDP boundary.
 export const safeJs = (
   strings: TemplateStringsArray,
   ...values: ReadonlyArray<unknown>
diff --git a/src/util/mutex.ts b/src/util/mutex.ts
index 08efe76..ad9e0c1 100644
--- a/src/util/mutex.ts
+++ b/src/util/mutex.ts
@@ -1,8 +1,3 @@
-/**
- * Lightweight async mutex (~10 lines). Acquire returns a release function.
- * When the mutex is free, acquire() resolves immediately. When held,
- * callers are queued and execute serially in FIFO order.
- */
 export type Mutex = {
   acquire(): Promise<() => void>;
 };
diff --git a/src/util/sharp-shim.ts b/src/util/sharp-shim.ts
index 36dd536..d7adb5f 100644
--- a/src/util/sharp-shim.ts
+++ b/src/util/sharp-shim.ts
@@ -1,10 +1,4 @@
-// Typed minimal shim for the optional `sharp` dependency. Sharp is a heavy
-// native module not installed in every workspace; we import dynamically and
-// distinguish "missing" (no install) from "error" (installed but threw).
-//
-// We declare only the surface we use. The dynamic import returns `unknown`
-// at the boundary; the cast inside loadSharp() is the documented escape
-// hatch — every other consumer sees the typed SharpFactory.
+// `sharp` is an optional dependency not installed in every workspace, so the import must stay dynamic and unresolvable to tsc.
 
 export type SharpInstance = {
   metadata(): Promise<{ width?: number; height?: number }>;
@@ -38,8 +32,7 @@ export const loadSharp = async (): Promise<SharpLoad> => {
     return { kind: "error", message: msg };
   }
   if (mod === null || mod === undefined) return { kind: "missing" };
-  // The CommonJS sharp module's default export IS the factory. ESM-wrapped
-  // sharp puts it on .default. Probe both.
+  // The CommonJS sharp module's default export IS the factory; ESM-wrapped sharp puts it on .default.
   const m = mod as { default?: unknown };
   const candidate: unknown = typeof m.default === "function" ? m.default : mod;
   if (typeof candidate !== "function") {
diff --git a/src/util/tool.ts b/src/util/tool.ts
index 76087bc..155ab00 100644
--- a/src/util/tool.ts
+++ b/src/util/tool.ts
@@ -57,10 +57,7 @@ export type BrowserToolDefinition<S extends TSchema> = {
   readonly ensureAlive?: boolean;
 };
 
-// Type-erased entry for the registry's heterogeneous TOOLS array.
-// renderCall accepts `never` so any concrete args type satisfies it via
-// function-parameter contravariance (a handler that takes SpecificT is
-// assignable to one that takes never, because never is a subtype of everything).
+// renderCall accepts `never` so any concrete args type satisfies it via function-parameter contravariance.
 export type AnyBrowserToolDefinition = Omit<BrowserToolDefinition<TSchema>, "renderCall" | "renderResult"> & {
   readonly renderCall?: (args: never, theme: Theme) => Component;
   readonly renderResult?: (result: AgentToolResult<unknown>, expanded: boolean, theme: Theme) => Component;
@@ -104,9 +101,6 @@ export const registerBrowserTool = (
   client: BrowserClient,
   def: AnyBrowserToolDefinition,
 ): void => {
-  // AnyBrowserToolDefinition is type-erased; we recover the schema-typed surface
-  // by casting def to the generic form. The cast is safe because defineBrowserTool
-  // ensures the handler, parameters, and renderCall were all created with the same S.
   type S = TSchema;
   const defRenderCall = def.renderCall;
   const defRenderResult = def.renderResult;
@@ -120,8 +114,7 @@ export const registerBrowserTool = (
     ...(defRenderCall
       ? {
           renderCall: (args: Static<S>, theme: Theme, _ctx: Parameters<NonNullable<ToolDefinition<S>["renderCall"]>>[2]) =>
-            // Cast from never->Component to unknown->Component: safe because at runtime
-            // args is always the concrete Static<S> value the tool was defined with.
+            // Sanctioned cast: at runtime args is always the concrete Static<S> value the tool was defined with.
             (defRenderCall as (args: unknown, theme: Theme) => Component)(args, theme),
         }
       : {}),
@@ -137,9 +130,6 @@ export const registerBrowserTool = (
       : {}),
     async execute(_toolCallId, args, signal, onUpdate, extensionCtx) {
       if (def.ensureAlive !== false) {
-        // Check daemon socket exists before attempting browser control.
-        // If missing, the user hasn't run /browser-setup yet. Return a clear
-        // error so the agent knows to direct the user to initialize.
         if (!(await daemonSocketMayExist())) {
           return toToolResult(
             {