feat: shell terminal, virtual keyboard fixes, settings font slider

- Add shell terminal: new tmux window spawned at project cwd, opened
  from the Terminal icon in the ChatView header; ShellTerminalView lets
  you navigate back to chat or jump to the Claude tmux terminal mode
- Fix system keyboard appearing on first terminal launch: ghostty-web
  calls focus() on a contenteditable div inside open(), triggering iOS
  keyboard before we can suppress it; patch HTMLElement.prototype.focus
  as a no-op for the synchronous duration of terminal.open()
- Add keyboard font-size slider in Settings
- Fix virtual keyboard button corner radius and depth scaling with key height
- Fix keybar gap/padding proportionality via heightScale factor
- Cap keybar font size so it does not grow when bar height is increased

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

src/lib/terminal/frontend-log.ts

@@ -0,0 +1,144 @@
+export type FrontendLogLevel = "debug" | "info" | "warn" | "error";
+
+export interface WebtermScopedLogger {
+  debug: (text: string, extra?: Record<string, unknown>) => void;
+  info: (text: string, extra?: Record<string, unknown>) => void;
+  warn: (text: string, extra?: Record<string, unknown>) => void;
+  error: (text: string, extra?: Record<string, unknown>) => void;
+}
+
+declare global {
+  interface Window {
+    webtermClientLog?: (text: string, extra?: Record<string, unknown>) => Promise<void>;
+    webtermClientLogSessionID?: string;
+    webtermClientBuildVersion?: string;
+    webtermLogs?: {
+      bug: WebtermScopedLogger;
+      ui: WebtermScopedLogger;
+      voice: WebtermScopedLogger;
+      ws: WebtermScopedLogger;
+    };
+  }
+}
+
+export const FRONTEND_BUILD_VERSION = "clawtap";
+
+function createFrontendLogSessionID(): string {
+  if (typeof crypto !== "undefined" && typeof crypto.randomUUID === "function") {
+    return crypto.randomUUID();
+  }
+  const chars = "abcdefghijklmnopqrstuvwxyz0123456789";
+  let out = "";
+  for (let i = 0; i < 24; i += 1) {
+    out += chars[Math.floor(Math.random() * chars.length)];
+  }
+  return out;
+}
+
+export const frontendLogSessionID = createFrontendLogSessionID();
+
+function normalizeFrontendLogValue(value: unknown): unknown {
+  if (value instanceof Error) {
+    return {
+      name: value.name,
+      message: value.message,
+      stack: value.stack,
+    };
+  }
+  if (Array.isArray(value)) {
+    return value.map((item) => normalizeFrontendLogValue(item));
+  }
+  if (value && typeof value === "object") {
+    return Object.fromEntries(
+      Object.entries(value as Record<string, unknown>).map(([key, item]) => [key, normalizeFrontendLogValue(item)])
+    );
+  }
+  return value;
+}
+
+function serializeFrontendLogContext(extra: Record<string, unknown> = {}): string {
+  const entries = Object.entries(extra);
+  if (entries.length === 0) {
+    return "";
+  }
+  try {
+    return JSON.stringify(Object.fromEntries(entries.map(([key, value]) => [key, normalizeFrontendLogValue(value)])));
+  } catch {
+    return String(extra);
+  }
+}
+
+export async function postFrontendLog(
+  level: FrontendLogLevel,
+  text: string,
+  extra: Record<string, unknown> = {}
+): Promise<void> {
+  const message = typeof text === "string" ? text.trim() : "";
+  if (!message) return;
+  try {
+    await fetch("/api/client-log", {
+      method: "POST",
+      headers: { "Content-Type": "application/json" },
+      credentials: "same-origin",
+      body: JSON.stringify({
+        session_id: frontendLogSessionID,
+        text: message,
+        frontend_version: FRONTEND_BUILD_VERSION,
+        level,
+        context: serializeFrontendLogContext(extra),
+      }),
+      keepalive: true,
+    });
+  } catch (error) {
+    console.warn("[webterm] Failed to post client log:", error);
+  }
+}
+
+function logFrontend(level: FrontendLogLevel, text: string, extra: Record<string, unknown> = {}): void {
+  void postFrontendLog(level, text, extra);
+}
+
+function logFrontendDebug(text: string, extra: Record<string, unknown> = {}): void {
+  logFrontend("debug", text, extra);
+}
+
+function logFrontendInfo(text: string, extra: Record<string, unknown> = {}): void {
+  logFrontend("info", text, extra);
+}
+
+function logFrontendWarn(text: string, extra: Record<string, unknown> = {}): void {
+  logFrontend("warn", text, extra);
+}
+
+function logFrontendError(text: string, extra: Record<string, unknown> = {}): void {
+  logFrontend("error", text, extra);
+}
+
+export function createScopedFrontendLogger(scope: string): WebtermScopedLogger {
+  const withScope = (extra: Record<string, unknown> = {}): Record<string, unknown> => ({
+    scope,
+    ...extra,
+  });
+  return {
+    debug: (text, extra = {}) => logFrontendDebug(text, withScope(extra)),
+    info: (text, extra = {}) => logFrontendInfo(text, withScope(extra)),
+    warn: (text, extra = {}) => logFrontendWarn(text, withScope(extra)),
+    error: (text, extra = {}) => logFrontendError(text, withScope(extra)),
+  };
+}
+
+export const bugLog = createScopedFrontendLogger("bug");
+export const uiLog = createScopedFrontendLogger("ui");
+export const voiceLog = createScopedFrontendLogger("voice");
+export const wsLog = createScopedFrontendLogger("ws");
+
+window.webtermClientLog = (text: string, extra: Record<string, unknown> = {}) =>
+  postFrontendLog("info", text, extra);
+window.webtermClientLogSessionID = frontendLogSessionID;
+window.webtermClientBuildVersion = FRONTEND_BUILD_VERSION;
+window.webtermLogs = {
+  bug: bugLog,
+  ui: uiLog,
+  voice: voiceLog,
+  ws: wsLog,
+};