Reproduction link or steps

https://github.com/e965/rolldown-cli-repro-1
https://github.com/e965/rolldown-cli-repro-1/actions/runs/28687552017/job/85082891748

What is expected?

The CLI should correctly parse --codeSplitting false and --codeSplitting=false as a boolean false value, as documented in the CLI help output:

--codeSplitting <codeSplitting> Code splitting options (true, false, or object).

Running Rolldown with either of these commands should disable code splitting and produce a single output file, equivalent to the deprecated --inlineDynamicImports behavior:

rolldown src/index.js --codeSplitting false --format=esm --platform=node --minify --sourcemap --file=dist/index1.js
rolldown src/index.js --codeSplitting=false --format=esm --platform=node --minify --sourcemap --file=dist/index2.js

What is actually happening?

Both CLI forms fail because the value false is treated as a string instead of being parsed as a boolean:

[error] Invalid value for option codeSplitting: Invalid type: Expected (boolean | Object) but received "false".

This happens with both:

--codeSplitting false
--codeSplitting=false

However, the deprecated --inlineDynamicImports option still works and prints a warning suggesting codeSplitting: false instead:

[warn] `inlineDynamicImports` option is deprecated, please use `codeSplitting: false` instead.

So there is currently no working CLI equivalent for disabling code splitting through the documented codeSplitting option.

System Info

System:
    OS: Linux 6.18 Ubuntu 24.04.4 LTS 24.04.4 LTS (Noble Numbat)
    Shell: 5.2.21 - /bin/bash
  Binaries:
    Node: 24.13.0 - /home/user/.nvm/versions/node/v24.13.0/bin/node
    npm: 11.12.1 - /home/user/.nvm/versions/node/v24.13.0/bin/npm
  npmPackages:
    rolldown: ^1.1.4 => 1.1.4

Any additional comments?

This may also happen with other CLI options that require a boolean argument, but I have not tested this.