Native CLI: rebuild deka_cli on the deka-cli-core registry

[samifouad]

What changed

The native deka binary hand-parsed std::env::args() with an if-chain and decided exit codes inline. This PR rebuilds it on the deka-cli-core registry (dcore, no V8 link — the legacy cli crate is untouched and not a dependency):

• One registry (deka_cli/src/cli.rs): all seven commands (run/start, dev, check, build/compile, test, init) registered with owner/category/summary; flags --entry/--outfile/--exercise registered per command; global --help/--version.
• One dispatcher: dispatch(registry, argv) -> i32 — argv in, exit code out, so tests drive every command without spawning a process. Usage errors (unknown command/flag, missing value, extra positionals) exit 2 with did-you-mean suggestions; runtime failures exit 1. main is the single exit point.
• Outcome shim: deka-cli-core 0.5.0 handlers are fn(&Context) with no return, so each handler stores its Result in one Outcome slot in the context extensions and the dispatcher maps it to the exit code. Registry: handlers return an exit status, flags carry typed values cli-core#22 (0.6.0, status-returning handlers + typed flags) replaces exactly this shim — adoption is deleting it.
• Truthful help: dcore::help::render_command_help is bypassed for command help because its curated copy describes the legacy V8 CLI (build --bundle --minify emitting JavaScript); native command help renders from the registry instead. Global help still uses the dcore renderer.

Behavior preserved

Same commands, aliases and flags; bare .ds/.dsx still means run; embedded-payload apps and --exercise unchanged — the existing integration suite (crates/deka_cli/tests/native_cli.rs: script runs, deka test counts, build + codesign + relocated app, desktop --exercise 3 → Count: 3, cycles, init) passes unmodified. Deliberate tightenings: unknown command/flag and --outfile on run now exit 2 (GNU usage convention, matching the legacy CLI) instead of 1.

Evidence

• cargo check --locked --workspace --all-targets → 0

• cargo clippy --locked --workspace --all-targets --all-features → 0, no warnings in deka_cli

• cargo test --locked -p deka_cli → 11 lib + 7 integration passed, 0 failed

• Revert proof: stubbing dispatch to the pre-registry "everything succeeds" behavior makes 7 of the 9 new lib tests fail (unknown_command_and_bad_flags_are_usage_errors, run_rejects_usage_mistakes, run_executes_script_and_maps_failures, check_accepts_valid_source_and_rejects_invalid, init_scaffolds_once, test_reports_counts, build_produces_an_executable_with_an_embedded_payload)

• Manual transcript (debug binary):

  $ deka --version   → deka 0.60.1 (Rust VM)
  $ deka frobnicate  → deka: unknown argument `frobnicate`     (exit 2)
  $ deka --outfile   → deka: missing value for `--outfile`     (exit 2)
  $ deka hello.ds    → hello from registry cli                 (exit 0, bare path = run)
  $ deka build --help → Usage + --entry/--outfile flags
  $ deka run --help   → Usage + --entry/--exercise flags
  $ deka --help       → registry-rendered global help, Getting Started block filtered to native commands
  

Docs: docs/dekascript/native-cli.mdx gains a Command line section (registry, deka <command> --help, exit-code convention).

closes #1204
-kimi

Update: now on deka-cli-core 0.6.0 (bd672282)

The first commit built the registry on 0.5.0 with an Outcome slot shim. deka-cli-core 0.6.0 (dekaruntime/cli-core#26, published as v0.6.0) has since shipped, and the second commit adopts it:

• Handlers return Result<ExitStatus, CommandError> — the shim is deleted. Registry::run_argv is the single place that prints errors and maps them to exit codes.
• Flag values go through typed accessors (ctx.param::<usize>("--exercise")?) — bad values are usage errors in the registry's one format.
• dcore is dropped (it stays on 0.5.0 for the legacy CLI; its curated help also describes that CLI) — help renders locally from the registry; tests()/build() write through the context output sinks, so tests assert 1 passed, 0 failed and the OK line in-process via run_captured.
• Transcript: deka frobnicate → unknown argument \frobnicate`(2);deka run x.ds --exercise NaN→invalid value for `--exercise`: invalid digit found in string(2);deka check x.ds→OK x.ds` (0).
• Gates re-run: cargo check --locked --workspace --all-targets → 0; cargo clippy --locked --workspace --all-targets --all-features → 0 (no deka_cli warnings); cargo test --locked -p deka_cli → 11 lib + 7 integration green. Revert proof: making handlers unable to report failure fails init_scaffolds_once and test_reports_counts.