* ⚡️ refactor: Migrate @librechat/api build to tsdown

Replace Rollup with tsdown (rolldown + oxc isolated-declarations) for the
@librechat/api package build, mirroring the merged data-schemas migration.

- Add tsdown.config.mjs (cjs output, oxc dts, externalize all bare deps,
  bundle first-party `~/` + relative imports)
- Annotate exports for isolatedDeclarations (codefix-driven). Collapse the
  tokens.ts model->token maps to Record<string, Record<string, number>> and
  switch validation.ts's runtime `files` field from z.any() to z.unknown()
  so no explicit `any` is introduced
- Repoint package.json main/types/exports to tsdown's .cjs/.d.cts output
- Add src/telemetry.ts entry shim so the two index.ts entries don't collide
  in oxc's flat dts output (stable dist/telemetry.{cjs,d.cts})
- Delete rollup.config.js

Build time ~36s -> ~0.5s. No runtime behavior change: 5712 unit tests pass,
both entries load via require(), legacy /api consumes them unchanged.

* 👷 ci: Hash packages/api/tsdown.config.mjs in build-api cache keys

The build-api cache keys hashed `packages/api/server-rollup.config.js`,
which never existed (api used `rollup.config.js`, now removed) — a copy-paste
artifact from the data-provider key that matched no file. Replace it with the
new `packages/api/tsdown.config.mjs` so edits to the build config (entry,
format, externals) bust the api build cache, matching the data-schemas key.

…#13597)

Replace the Rollup + `rollup-plugin-typescript2` build with a split
pipeline: tsdown (rolldown) bundles the JS in ~0.2s, and plain `tsc`
emits the declarations to `dist/types` (~2s). Full cold build drops from
~9.2s to ~2.5s (~3.6x) with zero source changes.

Unlike data-schemas, the fast oxc/isolated-declarations dts path isn't
viable here: the package's 78 exported zod schemas produce 374
`isolatedDeclarations` errors (TS9013/TS9038) and a `z.ZodType<T>`
annotation would break the 76 downstream `.extend`/`.shape`/`.pick`
usages. Plain `tsc` keeps the rich zod types intact, and since dts was
never the bottleneck (rollup-plugin-typescript2 was), the win stands.

- dts stays unbundled in `dist/types/` — identical to the prior output,
  so the existing deep `dist/types` imports and the exports `types`
  paths are unchanged.
- ESM output renamed `index.es.js` -> `index.mjs` (via the exports map;
  no consumer hardcodes the old path). cjs/types paths unchanged.
- `./react-query` now emits a real cjs build + types — the exports map
  already promised them, but Rollup only ever built the esm file.
- Kept `rollup` + the plugins used by `server-rollup.config.js`
  (the `rollup:api` server-bundle smoke test in backend-review.yml);
  removed only the deps used solely by the deleted `rollup.config.js`.
- Repointed CI build-cache keys from `rollup.config.js` to
  `tsdown.config.mjs`.

* ⚡ refactor: Migrate @librechat/client build from Rollup to tsdown

Mirrors the data-schemas migration. Replaces Rollup (rpt2 + postcss) with
tsdown (rolldown + oxc); the package build drops from tens of seconds to ~0.3s.

- Emit isolated-declaration .d.ts via oxc (dts.oxc) and enforce
  isolatedDeclarations in tsconfig for editor DX (source made clean: explicit
  export type annotations added across src, no `any`).
- Extract component CSS to dist/style.css so the CJS output stays valid
  CommonJS (the prior postcss runtime-injection produced an ESM import in the
  CJS bundle that breaks jest/require). Imported once in the client app entry;
  Vite bundles it for the app.
- Repoint package.json to dual .mjs/.cjs + .d.mts/.d.cts and add ./style.css
  and ./package.json exports.
- Update CI build-cache keys to hash tsdown.config.mjs; remove rollup.config.js.

* 🔧 chore: address Codex review on client tsdown migration

- Add tsdown.config.mjs to turbo.json build `inputs` so changes to the new
  bundler config invalidate the Turbo cache (the shared inputs only listed the
  rollup configs). Also covers the already-migrated data-schemas.
- Name the memoized default export (ControlComboboxMemo) instead of the
  codefix-generated `_default_1`, for clearer stack traces / grepping.

…pi` (#13600)

The tsdown migration (#13595) externalizes all third-party imports
(Rollup inlined them), so several modules the api source imports must be
present at runtime. Six were not, causing production (`npm ci --omit=dev`)
to crash on boot with `Cannot find module 'get-stream'` (then the next).

Fixed following the package's existing convention — packages/api declares
runtime libs as `peerDependencies`, and the `/api` app provides them as
real `dependencies` (how express/mongoose/sharp already resolve):

- `api/package.json` (the prod app, the provider): add the 3 that were
  missing — `get-stream`, `jszip`, `mongodb`. (`dedent`/`lodash`/`nanoid`
  were already provided by /api.)
- `packages/api/package.json`: add all 6 to `peerDependencies` (the
  contract) and to `devDependencies` (workspace build/tests), matching
  the existing `mammoth`/`pdfjs-dist`/`sanitize-html` dev+peer pattern.
  `jszip`/`mongodb` move out of dev-only (were pruned in production).

Pinned to CJS-compatible majors (get-stream@6, nanoid@3). Verified the
built bundle has zero undeclared externals and the 3 newly-provided deps
are production (non-dev) in the lockfile, so they survive `--omit=dev`.