feat: Make deployment operations discoverable

[nfebe]

Make the CLI self-documenting enough to deploy a stack without reading agent source. Operation help exposes request contracts and plan support. Interactive presentation stays separate from raw script output.

[sourceant]

Code Review Summary

This pull request significantly enhances the FlatRun CLI's discoverability and interactive capabilities. It transitions the command-line entry point to a structured Cobra-based architecture, enabling features like shell completion and a more intuitive help system. The introduction of OpenAPI-driven request skeletons and 'plan' support allows users to preview operations without deep-diving into agent source code. Additionally, the presentation layer has been modernized with terminal-aware styling and responsive tables.

🚀 Key Improvements

• Implemented per-operation help that dynamically exposes request fields, types, and permissions directly from the agent's OpenAPI specification.
• Added support for --generate-cli-skeleton, providing a JSON template for complex request bodies.
• Introduced a --plan mode for operations that declare support in the agent, enabling safe previews of changes.
• Improved the image deployment flow (deployment image set) to automatically detect and update environment variables referenced in Docker Compose files, favoring environment overrides over YAML mutations.
• Modernized terminal output using lipgloss for semantic color-coding of statuses and responsive table layouts that wrap to terminal width.

💡 Minor Suggestions

• The version comparison logic in clientTrackNewer uses fmt.Sscanf with %d.%d, which is sufficient for major.minor tracking but might omit patch-level nuances in complex pre-release strings. For a simple version warning, this is acceptable.

[sourceant]

Review complete. No specific code suggestions were generated. See the overview comment for a summary.

[sourceant]

Review complete. See the overview comment for a summary.

[sourceant]

OpenAPI enum values can be of any type (e.g., integers, booleans), not just strings. Defining this as []string will cause json.Unmarshal to fail if the agent returns a specification containing non-string enums (like integer status codes).

Suggested change

	Enum []string `json:"enum"`
	Enum []any `json:"enum"`

[sourceant]

Using strings.TrimSpace on credentials will remove leading and trailing whitespace. While this is often intended to strip a trailing newline from stdin (e.g., via printf), it can corrupt API keys or passwords that legitimately contain spaces. It is safer to specifically trim only the trailing line ending.

Suggested change

	body["api_key"] = strings.TrimSpace(string(credential))
	body["api_key"] = strings.TrimRight(string(credential), "\r\n")
	} else {
	body["username"] = username
	body["password"] = strings.TrimRight(string(credential), "\r\n")

[sourceant]

Review complete. No specific code suggestions were generated. See the overview comment for a summary.