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-derive.ts

@@ -0,0 +1,128 @@
+/**
+ * ACP model/mode derivation — adapted from Paseo acp-agent.ts.
+ */
+import type {
+  SessionConfigOption,
+  SessionModelState,
+  SessionModeState,
+} from '@agentclientprotocol/sdk';
+import type { ProviderMode, ProviderModel, ThinkingOption } from './provider-types.js';
+
+type SelectConfigOption = Extract<SessionConfigOption, { type: 'select' }>;
+
+interface SelectConfigChoice {
+  value: string;
+  name: string;
+  description?: string | null;
+  group?: string;
+}
+
+function findSelectConfigOption({
+  configOptions,
+  category,
+  id,
+}: {
+  configOptions: SessionConfigOption[] | null | undefined;
+  category: string;
+  id?: string;
+}): SelectConfigOption | null {
+  const option = configOptions?.find(
+    (entry): entry is SelectConfigOption =>
+      entry.type === 'select' && entry.category === category && (!id || entry.id === id),
+  );
+  return option ?? null;
+}
+
+function flattenSelectOptions(options: SelectConfigOption['options']): SelectConfigChoice[] {
+  const flattened: SelectConfigChoice[] = [];
+  for (const option of options) {
+    if ('value' in option) {
+      flattened.push(option);
+      continue;
+    }
+    for (const groupOption of option.options) {
+      flattened.push({ ...groupOption, group: option.group });
+    }
+  }
+  return flattened;
+}
+
+function deriveSelectorOptions(
+  configOptions: SessionConfigOption[] | null | undefined,
+  category: string,
+): ThinkingOption[] {
+  const option = findSelectConfigOption({ configOptions, category });
+  if (!option) return [];
+
+  return flattenSelectOptions(option.options).map((value) => ({
+    id: value.value,
+    label: value.name,
+    isDefault: value.value === option.currentValue,
+  }));
+}
+
+export function deriveModesFromACP(
+  fallbackModes: ProviderMode[],
+  modeState?: SessionModeState | null,
+  configOptions?: SessionConfigOption[] | null,
+): { modes: ProviderMode[]; currentModeId: string | null } {
+  if (modeState?.availableModes?.length) {
+    return {
+      modes: modeState.availableModes.map((mode) => ({
+        id: mode.id,
+        label: mode.name,
+        description: mode.description ?? undefined,
+      })),
+      currentModeId: modeState.currentModeId ?? null,
+    };
+  }
+
+  const modeOption = findSelectConfigOption({ configOptions, category: 'mode' });
+  if (modeOption) {
+    const flatOptions = flattenSelectOptions(modeOption.options);
+    return {
+      modes: flatOptions.map((option) => ({
+        id: option.value,
+        label: option.name,
+        description: option.description ?? undefined,
+      })),
+      currentModeId: modeOption.currentValue,
+    };
+  }
+
+  return { modes: fallbackModes, currentModeId: null };
+}
+
+export function deriveModelDefinitionsFromACP(
+  models: SessionModelState | null | undefined,
+  configOptions?: SessionConfigOption[] | null,
+): ProviderModel[] {
+  const thinkingOptions = deriveSelectorOptions(configOptions, 'thought_level');
+  const defaultThinkingOptionId = thinkingOptions.find((o) => o.isDefault)?.id;
+
+  if (models?.availableModels?.length) {
+    return models.availableModels.map((model) => ({
+      id: model.modelId,
+      label: model.name,
+      description: model.description ?? undefined,
+      isDefault: model.modelId === models.currentModelId,
+      thinkingOptions: thinkingOptions.length > 0 ? thinkingOptions : undefined,
+      defaultThinkingOptionId: defaultThinkingOptionId ?? undefined,
+    }));
+  }
+
+  const modelOptions = deriveSelectorOptions(configOptions, 'model');
+  return modelOptions.map((option) => ({
+    id: option.id,
+    label: option.label,
+    isDefault: option.isDefault,
+    thinkingOptions: thinkingOptions.length > 0 ? thinkingOptions : undefined,
+    defaultThinkingOptionId: defaultThinkingOptionId ?? undefined,
+  }));
+}
+
+export function findThoughtLevelConfigId(
+  configOptions: SessionConfigOption[] | null | undefined,
+): string | null {
+  return findSelectConfigOption({ configOptions, category: 'thought_level' })?.id ?? null;
+}