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>

.forgejo/workflows/ci.yml

@@ -2,7 +2,7 @@ name: ci
 
 # Build the language toolchain from its IR seed and run the regression suites on
 # every push to main and every pull request. Until this landed the only workflow
-# was docs.yml, so nothing gated a change on `x test` / `x test-tools` or on the
+# was docs.yml, so nothing gated a change on `ludic dev test` / `ludic dev test-tools` or on the
 # compiler even building from the seed. See also bootstrap.yml, which proves the
 # C-free self-rebuild reproduces the seed byte-for-byte.
 on:
@@ -45,7 +45,7 @@ jobs:
           # The toolchain is macOS-first; on this Linux runner it links against a
           # tiny C-free IR shim that supplies the Darwin standard-stream globals
           # (__stdoutp/__stderrp) over glibc's stdout/stderr. Injected through
-          # LUDIC_CC so every clang invocation — the seed bootstrap, `x build`,
+          # LUDIC_CC so every clang invocation — the seed bootstrap, `ludic dev build`,
           # and each compiled test program — picks it up. Absolute path so it
           # still resolves if a step changes directory.
           echo "LUDIC_CC=clang-16 $(pwd)/tools/ci/linux_stdio_shim.ll" >> "$GITHUB_ENV"
@@ -60,20 +60,20 @@ jobs:
           # pre-built binaries: the language builds itself from source + seed.
           mkdir -p bin
           clang-16 tools/ci/linux_stdio_shim.ll selfhost/ludicc.seed.ll -o bin/ludicc
-          bin/ludicc tools/x/main.ludic -o bin/x
-          bin/x build
+          bin/ludicc tools/ludic-cli/main.ludic -o bin/ludic
+          bin/ludic dev build
 
-      - name: Regression suite (x test)
-        run: bin/x test
+      - name: Regression suite (ludic dev test)
+        run: bin/ludic dev test
 
-      - name: Editor-toolchain suite (x test-tools)
+      - name: Editor-toolchain suite (ludic dev test-tools)
         # Grammar/lexer/vocabulary sync, ludic-fmt idempotence (the project's
         # formatting contract — hand alignment is deliberately preserved, so the
         # gate is fmt(fmt(x)) == fmt(x), not fmt(x) == x), and the JSON/XML editor
         # assets. Cross-file LSP behaviour and the golden renders are macOS-ABI
         # bound and skip here — visibly — until the runtime's directory walk and
         # windowing are portable.
-        run: bin/x test-tools
+        run: bin/ludic dev test-tools
 
       - name: Docs cover the implementation
         run: |
@@ -81,9 +81,9 @@ jobs:
           # The whole docs toolchain is written in Ludic and runs through x —
           # no Python anywhere. check-impl / check-vocabulary / check-docs guard
           # the sources; docs-gen builds the site and docs-check is its coverage
-          # + integrity guard. (check-vocabulary also runs in `x test-tools`.)
-          bin/x check-impl
-          bin/x check-vocabulary
-          bin/x check-docs
-          bin/x docs-gen --out build/pages
-          bin/x docs-check build/pages
+          # + integrity guard. (check-vocabulary also runs in `ludic dev test-tools`.)
+          bin/ludic dev check-impl
+          bin/ludic dev check-vocabulary
+          bin/ludic dev check-docs
+          bin/ludic dev docs-gen --out build/pages
+          bin/ludic dev docs-check build/pages