feat(cli): install in one command, and call the CLI ludic

Getting started meant cloning the repository, bootstrapping a compiler and
learning a task runner called `x`. That is a contributor's workflow handed to
everyone who wants to try the language.

Installing is now one command:

    curl -fsSL https://workshopsoft.pages.workshopsoft.io/ludic/install.sh | sh

install.sh puts a complete toolchain — compiler, CLI, engine runtime, bundled
ludic.* packages, formatter, language server — in ~/.ludic and adds it to PATH.
Prebuilt artifacts are checksum-verified; where a platform has none, or the
release predates this layout, it bootstraps from the compiler's own IR seed with
clang. The docs site publishes the script beside the pages that quote it, so the
page and the script can never come from different releases.

`x` becomes `ludic`, and the surface splits by audience. A user of the language
sees `new`, `run`, `build`, `test`, `add`, `fmt`, `lsp`, `doctor`, `upgrade`;
`ludic new` scaffolds a project that builds and plays as it stands. Everything
the toolchain repo needs moved under `ludic dev` — build, test, reseed,
bootstrap-cfree, docs-gen, release — unchanged apart from the namespace. Those
tasks read arguments one position further along, so dispatch_dev sets a shift
and commands use arg_n()/arg_total() rather than each knowing its own depth.

Release artifacts become complete install roots (bin/ beside runtime/, packages/
and VERSION) rather than bare binaries, which is what the installer unpacks.
`ludic dev test` asserts the whole shape: it stages an install, puts it on PATH
with no LUDIC_HOME, and runs new -> build -> test through it.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

changes/README.md

@@ -1,7 +1,7 @@
 # Changesets
 
 A **changeset** is one small Markdown file describing a single user-facing change,
-dropped in this directory. `x release` consumes every changeset here into a new
+dropped in this directory. `ludic dev release` consumes every changeset here into a new
 `CHANGELOG.md` section, bumps `VERSION`, and deletes the consumed files.
 
 ## Format
@@ -14,7 +14,7 @@ the changelog. Markdown is fine.
 ```
 
 - `bump:` — `major`, `minor`, or `patch` (SemVer). The release version is bumped
-  by the **highest** level among the pending changesets (unless `x release <level>`
+  by the **highest** level among the pending changesets (unless `ludic dev release <level>`
   overrides it).
 - `type:` — the Conventional Commit type (`feat`, `fix`, `perf`, `docs`, …). It
   decides which group the change lands in: `feat` → **Features**, `fix` →
@@ -47,5 +47,5 @@ filename works except this `README.md`, which the release step always skips.
 Preview how the next release will read before cutting it — this writes nothing:
 
 ```bash
-x release --dry-run
+ludic dev release --dry-run
 ```

changes/install-and-ludic-cli.md

@@ -0,0 +1,34 @@
+bump: minor
+type: feat
+**One command installs Ludic, and `ludic` is the command you use.** Getting
+started no longer means cloning the repository and learning a task runner called
+`x`.
+
+- **`curl -fsSL https://workshopsoft.pages.workshopsoft.io/ludic/install.sh | sh`** installs a complete
+  toolchain — compiler, CLI, engine runtime, bundled `ludic.*` packages,
+  formatter and language server — into `~/.ludic` and puts it on your `PATH`.
+  Prebuilt artifacts are verified against a published checksum; where none
+  exists for the platform, the installer bootstraps from the compiler's own IR
+  seed with clang. Uninstalling is `rm -rf ~/.ludic`, and `ludic upgrade`
+  re-runs the same script.
+- **`ludic` replaces `x`** and is the only command a user of the language meets:
+  `ludic new` scaffolds a project that builds and plays as it stands, `ludic
+  run` / `ludic build` compile it (`--headless` for a deterministic render),
+  `ludic test` runs every `test` block in the project, and `ludic add` / `get` /
+  `update` / `verify` / `vendor` drive packages. `ludic fmt` and `ludic lsp` are
+  the formatter and language server, so an editor needs no path configuration.
+  `ludic doctor` reports whether the install is complete and usable.
+- **The toolchain's own tasks moved under `ludic dev`** — `dev build`, `dev
+  test`, `dev reseed`, `dev bootstrap-cfree`, `dev docs-gen`, `dev release` and
+  the rest are unchanged apart from the namespace. `bin/x` is gone; the
+  bootstrap is now `clang selfhost/ludicc.seed.ll -o bin/ludicc && bin/ludicc
+  tools/ludic-cli/main.ludic -o bin/ludic`.
+- **An install root is a first-class layout.** The compiler derives it from its
+  own location — the parent of its `bin/` directory — so `~/.ludic` and a repo
+  checkout are the same shape, and `$LUDIC_HOME` is no longer needed to build a
+  windowed game outside the repo. The bundled `ludic.*` packages resolve from
+  `$LUDIC_HOME/packages`, so `import "ludic.core/components.ludic"` works with no
+  `ludic_modules/` to set up. Release artifacts are complete install roots
+  (`bin/` beside `runtime/`, `packages/` and `VERSION`) rather than bare
+  binaries, and the installer ships with the documentation site it is served
+  from.

changes/per-artifact-checksums.md

@@ -2,7 +2,7 @@ bump: patch
 type: fix
 Release checksums are one `.sha256` file per artifact instead of a single
 `SHA256SUMS`. A release is assembled from more than one host — a Linux runner
-cannot build the macOS toolchain — and `x publish` never overwrites an asset that
+cannot build the macOS toolchain — and `ludic dev publish` never overwrites an asset that
 is already attached, so a shared `SHA256SUMS` was written by whichever host
 published first and then never covered anything added afterwards. Per-artifact
 names compose across hosts. Verify one with