v2.2-paseo-providers: Paseo provider stack + v2.2.1 pane-scoped chat fixes

Ship Paseo-equivalent provider snapshot, AgentComposerBar, ACP dispatch
rewrite with streaming/persist, permission prompts, and agent commands.
Follow-up: pane-scoped chat resolution, CoderMessageList tool timeline,
WS user-delta replace, and inference orphan tool_call stripping.
Archive openspec v2-2; update CHANGELOG and CURRENT.

Co-authored-by: Cursor <cursoragent@cursor.com>

apps/coder/src/services/acp-probe.ts

@@ -0,0 +1,155 @@
+/**
+ * Short-lived ACP probe — opens a session and reads models/modes from the response.
+ */
+import { spawn } from 'node:child_process';
+import {
+  ClientSideConnection,
+  type Client,
+  type NewSessionResponse,
+  type ReadTextFileRequest,
+  type ReadTextFileResponse,
+  type WriteTextFileRequest,
+  type WriteTextFileResponse,
+  type CreateTerminalRequest,
+  type CreateTerminalResponse,
+  type RequestPermissionRequest,
+  type RequestPermissionResponse,
+} from '@agentclientprotocol/sdk';
+import { deriveModesFromACP, deriveModelDefinitionsFromACP } from './acp-derive.js';
+import { getManifestDefaultModeId, getManifestModes } from './provider-manifest.js';
+import { resolveAcpSpawnArgs } from './acp-spawn.js';
+import { createAcpNdJsonStream } from './acp-stream.js';
+import type { ProviderModel, ProviderMode } from './provider-types.js';
+import type { AgentCommand } from './agent-commands-cache.js';
+
+const PROBE_TIMEOUT_MS = 30_000;
+
+export interface AcpProbeResult {
+  ok: boolean;
+  models: ProviderModel[];
+  modes: ProviderMode[];
+  defaultModeId: string | null;
+  commands: AgentCommand[];
+  error?: string;
+}
+
+function parseSessionResponse(session: NewSessionResponse, agent: string): AcpProbeResult {
+  const fallbackModes = getManifestModes(agent);
+  const { modes, currentModeId } = deriveModesFromACP(
+    fallbackModes,
+    session.modes,
+    session.configOptions,
+  );
+  const models = deriveModelDefinitionsFromACP(session.models, session.configOptions);
+
+  return {
+    ok: true,
+    models,
+    modes,
+    defaultModeId: currentModeId ?? getManifestDefaultModeId(agent),
+    commands: [],
+  };
+}
+
+export async function probeAcpProvider(
+  agent: string,
+  installPath: string,
+  cwd: string,
+): Promise<AcpProbeResult> {
+  const args = resolveAcpSpawnArgs(agent);
+  if (!args) {
+    return {
+      ok: false,
+      models: [],
+      modes: getManifestModes(agent),
+      defaultModeId: getManifestDefaultModeId(agent),
+      commands: [],
+      error: 'no ACP spawn args',
+    };
+  }
+
+  const child = spawn(installPath, args, {
+    cwd,
+    stdio: ['pipe', 'pipe', 'pipe'],
+    env: { ...process.env },
+  });
+
+  let killed = false;
+  const kill = () => {
+    if (!killed) {
+      killed = true;
+      child.kill('SIGTERM');
+      setTimeout(() => child.kill('SIGKILL'), 2_000);
+    }
+  };
+
+  const timeout = setTimeout(kill, PROBE_TIMEOUT_MS);
+
+  const probedCommands: AgentCommand[] = [];
+
+  try {
+    const stream = createAcpNdJsonStream(child);
+
+    const connection = new ClientSideConnection(
+      (_agentInterface): Client => ({
+        async sessionUpdate(params) {
+          const update = params.update;
+          if (update.sessionUpdate === 'available_commands_update') {
+            for (const cmd of update.availableCommands) {
+              probedCommands.push({
+                name: cmd.name,
+                description: cmd.description ?? undefined,
+              });
+            }
+          }
+        },
+        async requestPermission(params: RequestPermissionRequest): Promise<RequestPermissionResponse> {
+          const first = params.options[0];
+          if (first) {
+            return { outcome: { outcome: 'selected', optionId: first.optionId } };
+          }
+          return { outcome: { outcome: 'cancelled' } };
+        },
+        async readTextFile(_params: ReadTextFileRequest): Promise<ReadTextFileResponse> {
+          return { content: '' };
+        },
+        async writeTextFile(_params: WriteTextFileRequest): Promise<WriteTextFileResponse> {
+          return {};
+        },
+        async createTerminal(_params: CreateTerminalRequest): Promise<CreateTerminalResponse> {
+          return { terminalId: 'noop' };
+        },
+      }),
+      stream,
+    );
+
+    await connection.initialize({
+      protocolVersion: 1,
+      clientInfo: { name: 'boocoder-probe', version: '2.2.0' },
+      clientCapabilities: {},
+    });
+
+    const session = await connection.newSession({ cwd, mcpServers: [] });
+    const result = parseSessionResponse(session, agent);
+    result.commands = probedCommands;
+    await connection.closeSession({ sessionId: session.sessionId }).catch(() => {});
+    return result;
+  } catch (err) {
+    const message = err instanceof Error ? err.message : String(err);
+    return {
+      ok: false,
+      models: [],
+      modes: getManifestModes(agent),
+      defaultModeId: getManifestDefaultModeId(agent),
+      commands: probedCommands,
+      error: message,
+    };
+  } finally {
+    clearTimeout(timeout);
+    kill();
+    await new Promise<void>((resolve) => {
+      child.on('close', resolve);
+      setTimeout(resolve, 2_000);
+    });
+  }
+}