refactor(cli)!: split the contributor tool out of the ludic CLI

`ludic help` ended with a section titled "contributing to the toolchain itself",
listing bootstrap, reseed, docs-gen and release tasks. None of that is available
to someone who installed the language — those tasks need the repository — so the
shipped tool was advertising work its user cannot do, in a namespace they have to
read past to find `new` and `run`.

The tasks move to a second program, dev.ludic -> bin/ludic-dev, built from a
checkout and excluded from every release artifact. `ludic` keeps the project and
package commands and nothing else; `ludic dev …` now explains where the tasks
went instead of failing as an unknown command.

What this shook out: the two programs share prelude/build/project/pkg, so the
helpers each had accreted in whichever file first needed them — cc(),
ensure_ludicc, the string functions, title_case, cmd_version — moved to where
both can see them. The argument-shift indirection added for the `dev` namespace
is gone with the namespace, so commands read argv directly again.

`ludic-dev test` asserts the split rather than trusting it: the staged install
must build a project, and `ludic dev build` there must fail while naming
ludic-dev. install.sh keeps building older tags, whose bootstrap goes through
main.ludic.

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

tools/ludic-cli/toolchain.ludic

@@ -0,0 +1,44 @@
+# toolchain.ludic — building the toolchain's own binaries. Contributor-only:
+# this is what `ludic-dev build` does, and none of it ships to a user.
+# compile a Ludic source to a native binary in bin/ via ludicc + clang (-O2).
+# Returns true on success. Used for the CLI, the contributor tool and the editor
+# tools — every binary the toolchain builds of itself.
+function build_tool(name: pointer, src: pointer) -> bool {
+  let ll = `build/{name}.ll`
+  if not shq(`bin/ludicc {src} --emit-llvm -o {ll} 2>/dev/null`) { print(`build failed: {name} (compile)`); return false }
+  # write to a temp then move, so a running bin/ludic can rebuild itself in place
+  if not shq(`{cc()} -O2 {ll} -o bin/{name}.tmp`) { print(`build failed: {name} (link)`); return false }
+  run(`mv -f bin/{name}.tmp bin/{name} && rm -f {ll}`)
+  return true
+}
+
+# ---- build-cli: the self-hosted front-end binaries ---------------------------
+# Both ludicc and ludic are the SAME multi-call binary assembled from the IR seed
+# with clang alone; invoked as `ludic` it compiles-and-runs, as `ludicc` it just
+# compiles.
+function cmd_dev_build_cli() -> int {
+  run("mkdir -p bin build")
+  print("cc: selfhost/ludicc.seed.ll -> bin/ludicc  (from the IR seed, no C compiler)")
+  if not shq(`{cc()} selfhost/ludicc.seed.ll -o bin/ludicc`) { err("ludic: the seed did not assemble\n"); return 1 }
+  run("chmod +x bin/ludicc")
+  print("done. built bin/ludicc")
+  return 0
+}
+
+# ---- build: the whole toolchain --------------------------------------------
+# bin/ludic is what a user installs; bin/ludic-dev is this tool, which exists
+# only in a checkout and is never part of a release.
+function cmd_dev_build() -> int {
+  if cmd_dev_build_cli() != 0 { return 1 }
+  print("ludicc: tools/ludic-cli/main.ludic -> bin/ludic  (the CLI users install)")
+  if not build_tool("ludic", "tools/ludic-cli/main.ludic") { return 1 }
+  print("ludicc: tools/ludic-cli/dev.ludic  -> bin/ludic-dev  (this tool, rebuilding itself)")
+  if not build_tool("ludic-dev", "tools/ludic-cli/dev.ludic") { return 1 }
+  print("ludicc: tools/ludic-tools/fmt.ludic -> bin/ludic-fmt")
+  if not build_tool("ludic-fmt", "tools/ludic-tools/fmt.ludic") { return 1 }
+  print("ludicc: tools/ludic-tools/lsp.ludic -> bin/ludic-lsp")
+  if not build_tool("ludic-lsp", "tools/ludic-tools/lsp.ludic") { return 1 }
+  sync_vscode_grammar()
+  print("done. toolchain in bin/ (ludicc, ludic, ludic-dev, ludic-fmt, ludic-lsp)")
+  return 0
+}