Fix --deno-* option parsing and add cache command

[lambdalisue]

Summary

• Fix --deno-reload to work as boolean flag without requiring =
• Connect -r/--reload option to denoArgs (was parsed but unused)
• Add probitas cache command to pre-download scenario dependencies
• Add useConfig option to allow cache command to use deno.json/deno.lock

Why

1. --deno- Boolean Flags Were Broken*

Users reported that probitas run --deno-reload failed with an error. The issue was that extractDenoOptions() had overly strict validation that only allowed --deno-no-* options without values. This was incorrect because many Deno flags like --reload accept optional values:

• --reload (reload all dependencies)
• --reload=<mods> (reload specific modules)

The fix simplifies the logic: any --deno-* option without = is treated as a boolean flag, and options with = are treated as value options. This matches Deno's actual behavior.

2. -r/--reload Option Was Dead Code

The run/list commands parsed -r/--reload but never used the value. This has been connected to denoArgs so users can now use -r as a shorthand for --deno-reload.

3. Users Need Dependency Pre-caching

In CI/CD environments and offline workflows, users need to pre-download scenario dependencies before running tests. The new probitas cache command wraps deno cache with the same file discovery patterns as other CLI commands (fmt/lint/check), providing a consistent interface.

4. Cache Needs Config Files

Unlike fmt/lint/check which intentionally ignore deno.json (they use probitas-specific rules), the cache command needs to respect deno.json import maps and deno.lock to resolve dependencies correctly. Added useConfig option to DenoSubcommandOptions to make this configurable per command.

Test Plan

• Run deno task verify - all tests pass
• Test probitas run --deno-reload works without error
• Test probitas run -r works as shorthand
• Test probitas cache downloads dependencies and respects deno.json
• Test probitas cache -r forces re-download

[Copilot]

Pull request overview

This PR fixes --deno-* option parsing to support boolean flags without requiring = syntax, connects the existing -r/--reload option to the Deno subprocess, and adds a new probitas cache command for pre-downloading scenario dependencies.

Key changes:

• Simplified extractDenoOptions() to treat any --deno-* option without = as a boolean flag
• Connected -r/--reload shorthand to Deno subprocess in run and list commands
• Added probitas cache command with useConfig option to respect deno.json/deno.lock

Reviewed changes

Copilot reviewed 13 out of 13 changed files in this pull request and generated 2 comments.

Show a summary per file

File	Description
src/cli/utils.ts	Simplified extractDenoOptions() to remove strict validation and support boolean flags without =
src/cli/utils_test.ts	Added comprehensive test coverage for the new extractDenoOptions() behavior
src/cli/commands/run.ts	Connected -r/--reload option to denoArgs for Deno subprocess
src/cli/commands/list.ts	Connected -r/--reload option to denoArgs for Deno subprocess
src/cli/commands/cache.ts	New command to run deno cache on scenario files with config support
src/cli/commands/_deno.ts	Added supportReload and useConfig options to make the helper more flexible
src/cli/commands/mod.ts	Exported new cacheCommand
src/cli.ts	Wired up cache command in CLI dispatcher
assets/usage.txt	Added cache command to main help text
assets/usage-run.txt	Updated --deno-* option documentation with new syntax
assets/usage-list.txt	Updated --deno-* option documentation with new syntax
assets/usage-cache.txt	Added help text for new cache command
README.md	Added cache command to CLI examples

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[Copilot]

If a user provides both -r and --deno-reload, this will result in duplicate --reload flags being passed to the Deno subprocess. Consider checking if --reload is already present in denoArgs before adding it.

Suggested change

	// Add --reload to denoArgs if -r/--reload is specified
	const finalDenoArgs = parsed.reload ? [...denoArgs, "--reload"] : denoArgs;
	// Add --reload to denoArgs if -r/--reload is specified, avoiding duplicates
	const finalDenoArgs = parsed.reload && !denoArgs.includes("--reload")
	? [...denoArgs, "--reload"]
	: denoArgs;

[Copilot]

If a user provides both -r and --deno-reload, this will result in duplicate --reload flags being passed to the Deno subprocess. Consider checking if --reload is already present in denoArgs before adding it.

Suggested change

	// Add --reload to denoArgs if -r/--reload is specified
	const finalDenoArgs = parsed.reload ? [...denoArgs, "--reload"] : denoArgs;
	// Add --reload to denoArgs if -r/--reload is specified, avoiding duplicates
	const finalDenoArgs = parsed.reload && !denoArgs.includes("--reload")
	? [...denoArgs, "--reload"]
	: denoArgs;