feat: Add --no-prefix option to disable hostname prefix in output (pdsh -N compatibility)

[inureyes]

Summary

Add a new --no-prefix option to bssh that disables the hostname prefix in command output. This is a prerequisite for pdsh compatibility mode (meta-issue #91).

Parent Issue

Part of #91 (pdsh compatibility mode) - Phase 1: New Options for Feature Parity

Background

By default, bssh prefixes each line of output with the hostname to identify which node produced it:

[node1] Linux node1 5.15.0
[node2] Linux node2 5.15.0

pdsh provides -N option to disable this prefix, which is useful when:

• Parsing output programmatically
• Output is already self-identifying
• Cleaner display for single-node operations

Proposed Implementation

CLI Interface

# Default behavior (with prefix)
bssh -H "node1,node2" "uname -a"
# Output:
# [node1] Linux node1 5.15.0
# [node2] Linux node2 5.15.0

# With --no-prefix
bssh -H "node1,node2" --no-prefix "uname -a"
# Output:
# Linux node1 5.15.0
# Linux node2 5.15.0

Option Definition

#[arg(
    short = 'N',
    long = "no-prefix",
    help = "Disable hostname prefix in output lines\nUseful for programmatic parsing or cleaner display"
)]
pub no_prefix: bool,

Implementation Tasks

• Add --no-prefix / -N option to Cli struct in src/cli.rs
• Modify output formatting in src/ui.rs to respect this flag
• Ensure it works with all output modes (stream, TUI, normal)
• Add unit tests
• Update help text and examples

Acceptance Criteria

• --no-prefix removes [hostname] prefix from all output lines
• Works in stream mode (--stream)
• Works in normal output mode
• Works with output file mode (--output-dir) - file naming should still include hostname
• Does not affect TUI mode (TUI has its own display format)

Notes

• Short option -N does not conflict with existing bssh options
• Consider if this should also affect stderr output (probably yes)