Group help options into sections in command help

[fnando]

What

Group --help output into sections using clap's help_heading, so the shared signing, transaction, RPC, and global options no longer mix into the flat Options: list of every command.

The new layout (e.g. stellar tx new payment --help):

• Options: — the command's primary options
• RPC Options: — --rpc-url, --rpc-header, --network-passphrase, --network
• Transaction Options: — --source-account, --fee, --inclusion-fee, --build-only
• Global Options: — --config-dir, --quiet, --verbose, --no-cache, …
• Signing Options: — --sign-with-key, --hd-path, --sign-with-lab, --sign-with-ledger

This affects ~53 commands at once: all 22 stellar tx new subcommands, all 22 stellar tx operation add subcommands, the 5 stellar contract subcommands (deploy, upload, extend, restore, invoke), stellar contract asset deploy, stellar tx sign, stellar tx simulate, and stellar message sign.

The existing Options (RPC) / Options (Archive) / Options (Global) headings were renamed to RPC Options / Archive Options / Global Options for a consistent style across all sections.

Closes #2454.

Why

Until now, every transaction-building command listed all signing, transaction, source-account, and command-specific options in a single flat Options: block. The 8 shared options effectively buried the 3–7 primary options of each command, making --help hard to scan.

Grouping centrally on config::Args, sign_with::Args, and tx::Args fixes all 53 affected commands with a small edit and no behavioral change.

Known limitations

N/A — purely a --help rendering change. No CLI flags or behavior change.

[Copilot]

Pull request overview

This PR refactors CLI --help output to group commonly-flattened flags (RPC, transaction-building, global, signing) into distinct sections via clap’s help_heading, and regenerates the full markdown help docs accordingly.

Changes:

• Renamed existing help section headings (e.g., Options (RPC) → RPC Options) and introduced new headings for Signing Options and Transaction Options.
• Assigned help_heading to shared signing/transaction args (sign_with::Args, config::Args, tx::Args) so affected commands render grouped help.
• Regenerated FULL_HELP_DOCS.md from clap-markdown to reflect the new headings/sections.

Reviewed changes

Copilot reviewed 5 out of 6 changed files in this pull request and generated 1 comment.

Show a summary per file

File	Description
FULL_HELP_DOCS.md	Regenerated CLI help docs showing the new per-section headings across commands.
cmd/soroban-cli/src/config/sign_with.rs	Adds help_heading = HEADING_SIGNING to signing-related flags.
cmd/soroban-cli/src/config/mod.rs	Adds help_heading = HEADING_TRANSACTION to tx-related shared config flags.
cmd/soroban-cli/src/commands/tx/args.rs	Moves --build-only into the Transaction Options help section.
cmd/soroban-cli/src/commands/mod.rs	Renames heading constants and adds new constants for signing/transaction sections.
cmd/soroban-cli/src/commands/message/sign.rs	Groups message signing flags under Signing Options.

[leighmcculloch]

The --build-only flag in the following places is technically owned by each individual command at the moment, but I think should be grouped in a separate section. Maybe under Transaction Options.

• stellar contract extend
• stellar contract upload
• stellar contract deploy asset
• stellar contract invoke
• stellar contract restore
• stellar contract deploy wasm

Otherwise, looks good to me.