Remove undocumented ledger / ledger:N positional shorthand

[fnando]

What

Drop the undocumented ledger / ledger:N positional shorthand for UnresolvedMuxedAccount. Any command that takes an account argument (keys fund, keys address, tx sign, contract invoke --source-account, …) used to silently route to a connected Ledger device when given ledger or ledger:N. After this change, the only way to derive an address from a Ledger is the explicit --ledger flag.

UnresolvedMuxedAccount::Ledger(u32) is removed entirely. keys address/keys fund now derive the public key directly via signer::ledger::new(index).public_key() in their --ledger branch. resolve_muxed_account_sync collapses into resolve_muxed_account (the only async branch was Ledger), and several call sites lose now-unnecessary async/.await. The four dependent error variants (LedgerNotSupported, LedgerPrivateKeyRevealNotSupported, LedgerIsInvalidKeyName, and the ledger::Error From impl) become unreachable and are removed.

--sign-with-ledger and keys add ledger (the Secret::Ledger flow) are out of scope and untouched.

Closes #2559.

Why

The shorthand was introduced in #1627 and has been live since 2025-02-14, but it was never mentioned in --help, FULL_HELP_DOCS.md, the README, or any example. With #2557 introducing an explicit --ledger flag (and #2558 extending it to keys fund), the positional shorthand becomes a confusing and undocumented second way to reach the device — and one that can't be scoped per-command.

Known limitations

N/A

[Copilot]

Pull request overview

Removes the undocumented ledger / ledger:N positional shorthand routing in UnresolvedMuxedAccount, making Ledger address derivation available only via explicit per-command flags (e.g. keys address --ledger, keys fund --ledger). This simplifies account resolution by eliminating the only async branch (Ledger) and converting a number of call sites back to synchronous resolution.

Changes:

• Remove UnresolvedMuxedAccount::Ledger(u32) and the ledger/ledger:N parsing path; collapse resolve_muxed_account_sync into resolve_muxed_account.
• Update transaction-building / contract commands to use the new synchronous source_account() and resolve_muxed_account() APIs (dropping now-unnecessary async/.await).
• Update Ledger-related tests and add unit coverage ensuring ledger/ledger:N are no longer recognized as special shorthand.

Reviewed changes

Copilot reviewed 19 out of 19 changed files in this pull request and generated no comments.

Show a summary per file

File	Description
cmd/soroban-cli/src/tx/builder/asset.rs	Switch issuer resolution to the new sync resolve_muxed_account.
cmd/soroban-cli/src/config/mod.rs	Make source_account() synchronous and update callers accordingly.
cmd/soroban-cli/src/config/address.rs	Remove Ledger shorthand parsing/variant; rename sync resolver to resolve_muxed_account; add unit tests for shorthand removal.
cmd/soroban-cli/src/commands/tx/op/mod.rs	Make tx op dispatch synchronous (no remaining async dependency).
cmd/soroban-cli/src/commands/tx/op/add/mod.rs	Remove async from run() and from add_op call flow.
cmd/soroban-cli/src/commands/tx/mod.rs	Update tx operation execution to the new sync run().
cmd/soroban-cli/src/commands/tx/args.rs	Convert source-account resolution and add_op to synchronous use of resolve_muxed_account.
cmd/soroban-cli/src/commands/snapshot/create.rs	Use sync resolve_muxed_account for optional account resolution.
cmd/soroban-cli/src/commands/keys/public_key.rs	Derive Ledger public key directly via signer::ledger::new(index).public_key() in the --ledger path.
cmd/soroban-cli/src/commands/contract/upload.rs	Use sync config.source_account() when fetching sequence number.
cmd/soroban-cli/src/commands/contract/restore.rs	Use sync config.source_account() when fetching sequence number.
cmd/soroban-cli/src/commands/contract/mod.rs	Update contract id dispatch to sync run().
cmd/soroban-cli/src/commands/contract/invoke.rs	Use sync config.source_account() during account fetch.
cmd/soroban-cli/src/commands/contract/id/wasm.rs	Make run() sync and use sync config.source_account().
cmd/soroban-cli/src/commands/contract/id.rs	Make run() sync and adjust wasm dispatch accordingly.
cmd/soroban-cli/src/commands/contract/extend.rs	Use sync config.source_account() when fetching sequence number.
cmd/soroban-cli/src/commands/contract/deploy/wasm.rs	Use sync config.source_account() for source-account type check.
cmd/soroban-cli/src/commands/contract/deploy/asset.rs	Use sync config.source_account() when fetching sequence number.
cmd/crates/soroban-test/tests/it/integration/ledger/entry.rs	Update tests to use sync resolve_muxed_account API.