v2.3.0-sampling-params-ask-user: agent sampling params, ask_user_input in CoderPane, UX polish

Add top_p/top_k/min_p/presence_penalty to AGENTS.md frontmatter and thread
through inference (agents.ts parser → Agent type → stream-phase → sentinel
summaries). Null means omit from request body, preserving provider defaults.

Wire ask_user_input interactive card into both BooCoder frontends: the
CoderPane in BooChat's SPA (CoderMessageList now renders AskUserInputCard
instead of ToolCallLine for ask_user_input tool calls) and the standalone
coder SPA (MessageBubble + new AskUserInputCard + shadcn ui primitives).

Additional fixes: SessionLandingPage uses ChatInput with slash-command
support and lazy chat creation; Session.tsx hydrate-race fix for empty pane
promotion; AgentPicker wider dropdown with line-clamp; ModelPicker min-width;
Textarea converted to forwardRef; Recon agent added to AGENTS.md; codecontext
host port exposed in docker-compose.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

apps/coder/web/src/components/ui/radio-group.tsx

@@ -0,0 +1,56 @@
+import * as React from 'react';
+
+const RadioGroupContext = React.createContext<{
+  value: string | undefined;
+  onValueChange: (v: string) => void;
+  disabled?: boolean;
+} | null>(null);
+
+interface RadioGroupProps extends React.HTMLAttributes<HTMLDivElement> {
+  value?: string;
+  onValueChange?: (value: string) => void;
+  disabled?: boolean;
+}
+
+const RadioGroup = React.forwardRef<HTMLDivElement, RadioGroupProps>(
+  ({ className, value, onValueChange, disabled, ...props }, ref) => {
+    const ctx = React.useMemo(() => ({ value, onValueChange: onValueChange ?? (() => {}), disabled }), [value, onValueChange, disabled]);
+    return (
+      <RadioGroupContext.Provider value={ctx}>
+        <div
+          ref={ref}
+          role="radiogroup"
+          className={className}
+          {...props}
+        />
+      </RadioGroupContext.Provider>
+    );
+  },
+);
+RadioGroup.displayName = 'RadioGroup';
+
+interface RadioGroupItemProps extends React.InputHTMLAttributes<HTMLInputElement> {
+  value: string;
+}
+
+const RadioGroupItem = React.forwardRef<HTMLInputElement, RadioGroupItemProps>(
+  ({ className, value, ...props }, ref) => {
+    const ctx = React.useContext(RadioGroupContext);
+    if (!ctx) return <input ref={ref} type="radio" className={className} value={value} {...props} />;
+    const checked = ctx.value === value;
+    return (
+      <input
+        ref={ref}
+        type="radio"
+        checked={checked}
+        disabled={ctx.disabled}
+        onChange={() => ctx.onValueChange(value)}
+        className={className}
+        {...props}
+      />
+    );
+  },
+);
+RadioGroupItem.displayName = 'RadioGroupItem';
+
+export { RadioGroup, RadioGroupItem };