v2.1.0-provider-picker: BooCoder systemd migration + provider picker

- BooCoder moves from Docker to host systemd service (boocoder.service)
- Agent dispatch (ACP + PTY) switches from SSH to direct spawn/exec
- SSH helpers marked @deprecated (kept for one release cycle)
- Provider registry (5 providers: boocode, opencode, goose, claude, qwen)
- Agent probe with direct which/exec + model discovery (qwen settings, static claude models)
- GET /api/providers route with installed status, models, transport fallback
- ProviderPicker frontend component in CoderPane header
- External provider messages route through tasks row instead of inference enqueue
- Smart scroll: MessageList only auto-scrolls when near bottom (150px threshold)
- DB: available_agents gets models, label, transport columns
- Bug fix: loadContext SELECT includes allowed_read_paths
- Bug fix: cap hit sentinel inserted before buildMessagesPayload
- docker-compose.yml: boocoder service commented out, BOOCODER_URL env var added
- CLAUDE.md: updated docs for systemd, provider registry, JSONB gotcha, loadContext

apps/web/src/components/panes/CoderPane.tsx

@@ -10,6 +10,7 @@
 import { useCallback, useEffect, useRef, useState } from 'react';
 import { Code, Send, Check, X, RefreshCw } from 'lucide-react';
 import { MarkdownRenderer } from '@/components/MarkdownRenderer';
+import { ProviderPicker } from '@/components/ProviderPicker';
 import { cn } from '@/lib/utils';
 
 // ---------------------------------------------------------------------------
@@ -300,6 +301,8 @@ export function CoderPane({ sessionId }: Props) {
   const { changes, loading, refresh, approve, reject } = usePendingChanges(sessionId);
   const [input, setInput] = useState('');
   const [sending, setSending] = useState(false);
+  const [provider, setProvider] = useState('boocode');
+  const [model, setModel] = useState('qwen3.6-35b-a3b-mxfp4');
   const messagesEndRef = useRef<HTMLDivElement>(null);
   const inputRef = useRef<HTMLTextAreaElement>(null);
 
@@ -331,7 +334,11 @@ export function CoderPane({ sessionId }: Props) {
       const res = await fetch(`/api/coder/sessions/${sessionId}/messages`, {
         method: 'POST',
         headers: { 'content-type': 'application/json' },
-        body: JSON.stringify({ content: text }),
+        body: JSON.stringify({
+          content: text,
+          provider: provider !== 'boocode' ? provider : undefined,
+          model: model || undefined,
+        }),
       });
       if (res.ok) {
         const data = await res.json();
@@ -347,7 +354,7 @@ export function CoderPane({ sessionId }: Props) {
     } finally {
       setSending(false);
     }
-  }, [input, sending, sessionId, setMessages]);
+  }, [input, sending, sessionId, provider, model, setMessages]);
 
   const handleKeyDown = useCallback(
     (e: React.KeyboardEvent) => {
@@ -363,11 +370,18 @@ export function CoderPane({ sessionId }: Props) {
     <div className="flex flex-col h-full bg-background">
       {/* Header */}
       <div className="flex items-center gap-2 px-3 py-1.5 border-b border-border bg-muted/30 shrink-0">
-        <Code size={14} className="text-muted-foreground" />
-        <span className="text-xs font-medium text-muted-foreground">BooCoder</span>
+        <Code size={14} className="text-muted-foreground shrink-0" />
+        <ProviderPicker
+          provider={provider}
+          model={model}
+          onChange={(prov, mod) => {
+            setProvider(prov);
+            setModel(mod);
+          }}
+        />
         <span
           className={cn(
-            'inline-block w-1.5 h-1.5 rounded-full ml-auto',
+            'inline-block w-1.5 h-1.5 rounded-full ml-auto shrink-0',
             connected ? 'bg-green-500' : 'bg-red-500'
           )}
           title={connected ? 'Connected' : 'Disconnected'}