feat(combos): Cursor/Claude Default presets + bulk select/delete/strategy

- Add Cursor Default / Claude Default on Dashboard -> Combos to generate
  unprefixed combo names that match Cursor/Claude client model IDs,
  seeded with cu/... or cc/... so those clients can route through 9Router.
- Add multi-select bulk Delete and bulk Set strategy (Fallback / Round Robin / Fusion).
- Docs and unit tests for preset builder.

src/lib/comboPresets.js

@@ -0,0 +1,121 @@
+/**
+ * Build Cursor / Claude default combo presets.
+ * Combo names match client-native model IDs (no provider prefix);
+ * each is seeded with the matching prefixed 9router model so routing works.
+ */
+
+import { getProviderModels } from "open-sse/config/providerModels.js";
+import { CLI_TOOLS } from "@/shared/constants/cliTools";
+
+export const VALID_COMBO_NAME_REGEX = /^[a-zA-Z0-9_.\-]+$/;
+export const PRESET_SOURCES = new Set(["cursor", "claude"]);
+
+const CURSOR_ALIAS = "cu";
+const CLAUDE_ALIAS = "cc";
+
+/** Extra Claude Code aliases not listed in defaultModels. */
+const CLAUDE_EXTRA_ALIAS_TARGETS = {
+  default: "cc/claude-sonnet-5",
+  opusplan: "cc/claude-opus-5",
+};
+
+/**
+ * @param {string} name
+ * @returns {boolean}
+ */
+export function isValidComboPresetName(name) {
+  return typeof name === "string" && name.length > 0 && VALID_COMBO_NAME_REGEX.test(name);
+}
+
+/**
+ * @param {string} name
+ * @param {string[]} models
+ * @param {Set<string>} [seen]
+ * @returns {{ name: string, models: string[] }|null}
+ */
+function pushItem(name, models, seen) {
+  if (!isValidComboPresetName(name)) return null;
+  if (seen?.has(name)) return null;
+  if (!Array.isArray(models) || models.length === 0) return null;
+  seen?.add(name);
+  return { name, models };
+}
+
+/**
+ * @param {Array<{id?: string}|string>} modelList
+ * @param {string} providerAlias
+ * @param {Set<string>} seen
+ * @returns {{ name: string, models: string[] }[]}
+ */
+function itemsFromProviderModels(modelList, providerAlias, seen) {
+  const out = [];
+  for (const entry of modelList || []) {
+    const id = typeof entry === "string" ? entry : entry?.id;
+    if (!id) continue;
+    const item = pushItem(id, [`${providerAlias}/${id}`], seen);
+    if (item) out.push(item);
+  }
+  return out;
+}
+
+/**
+ * Build Cursor default presets.
+ * Prefer live catalog when provided; otherwise static cu registry.
+ * @param {{ liveModels?: Array<{id: string}|string> }} [opts]
+ * @returns {{ name: string, models: string[] }[]}
+ */
+export function buildCursorPresetItems(opts = {}) {
+  const seen = new Set();
+  const live = Array.isArray(opts.liveModels) ? opts.liveModels : null;
+  if (live?.length) {
+    return itemsFromProviderModels(live, CURSOR_ALIAS, seen);
+  }
+  return itemsFromProviderModels(getProviderModels(CURSOR_ALIAS), CURSOR_ALIAS, seen);
+}
+
+/**
+ * Build Claude default presets from cc registry + Claude Code aliases.
+ * @returns {{ name: string, models: string[] }[]}
+ */
+export function buildClaudePresetItems() {
+  const seen = new Set();
+  const out = itemsFromProviderModels(getProviderModels(CLAUDE_ALIAS), CLAUDE_ALIAS, seen);
+
+  const claudeTool = CLI_TOOLS.claude || {};
+  for (const entry of claudeTool.defaultModels || []) {
+    const name = entry.alias || entry.id;
+    const target = entry.defaultValue;
+    if (!name || !target) continue;
+    const item = pushItem(name, [target], seen);
+    if (item) out.push(item);
+  }
+
+  for (const alias of claudeTool.modelAliases || []) {
+    if (seen.has(alias)) continue;
+    const target = CLAUDE_EXTRA_ALIAS_TARGETS[alias];
+    if (!target) continue;
+    const item = pushItem(alias, [target], seen);
+    if (item) out.push(item);
+  }
+
+  return out;
+}
+
+/**
+ * @param {"cursor"|"claude"} source
+ * @param {{ liveModels?: Array<{id: string}|string>, existingNames?: Iterable<string> }} [opts]
+ * @returns {{ name: string, models: string[], exists: boolean }[]}
+ */
+export function buildPresetItems(source, opts = {}) {
+  if (!PRESET_SOURCES.has(source)) return [];
+
+  const items = source === "cursor"
+    ? buildCursorPresetItems({ liveModels: opts.liveModels })
+    : buildClaudePresetItems();
+
+  const existing = new Set(opts.existingNames || []);
+  return items.map((item) => ({
+    ...item,
+    exists: existing.has(item.name),
+  }));
+}