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/coder/src/services/provider-registry.ts

@@ -0,0 +1,46 @@
+export interface ProviderDef {
+  name: string;
+  label: string;
+  transport: 'native' | 'acp' | 'pty';
+  modelSource: 'llama-swap' | 'static';
+  staticModels?: Array<{ id: string; label: string }>;
+}
+
+export const PROVIDERS: ProviderDef[] = [
+  {
+    name: 'boocode',
+    label: 'BooCoder',
+    transport: 'native',
+    modelSource: 'llama-swap',
+  },
+  {
+    name: 'opencode',
+    label: 'OpenCode',
+    transport: 'acp',
+    modelSource: 'llama-swap',
+  },
+  {
+    name: 'goose',
+    label: 'Goose',
+    transport: 'acp',
+    modelSource: 'llama-swap',
+  },
+  {
+    name: 'claude',
+    label: 'Claude Code',
+    transport: 'pty',
+    modelSource: 'static',
+    staticModels: [
+      { id: 'claude-opus-4-20250514', label: 'Opus 4' },
+      { id: 'claude-sonnet-4-20250514', label: 'Sonnet 4' },
+    ],
+  },
+  {
+    name: 'qwen',
+    label: 'Qwen Code',
+    transport: 'pty',
+    modelSource: 'static',
+  },
+];
+
+export const PROVIDERS_BY_NAME = new Map(PROVIDERS.map((p) => [p.name, p]));