Add setup alias subcommand and automatic bash/zsh alias setup in v0k setup (plus version bump to 0.1.8)

[Copilot]

setup currently configures AI settings only, while shell alias/function integration is manual and easy to miss. This change adds a dedicated alias setup subcommand and wires the same step into the end of v0k setup when the shell is configurable (bash/zsh).

• CLI changes

  • Added v0k setup alias as a dedicated subcommand to install shell integration independently.
  • Extended v0k setup command dispatch to support setup subcommands.

• Setup flow behavior

  • After interactive config is saved, v0k setup now attempts shell integration install as the final step.
  • Shell detection targets configurable Unix shells (bash, zsh) via SHELL.

• Shell integration installation

  • Adds integration to ~/.bashrc or ~/.zshrc based on detected shell.
  • Uses idempotent append logic with integration block markers to avoid duplicate writes.
  • Prints clear status for added/already-configured/skipped cases.

• Single-source integration template

  • Reused one shared v0k() integration function string for:
    • fix missing-command hint output
    • setup alias and setup auto-install content
  • Removes duplicated alias/function text maintenance.

• Docs update

  • README now documents:
    • automatic shell integration during v0k setup
    • standalone v0k setup alias usage

• Version bump (feedback follow-up)

  • Bumped version from 0.1.7 to 0.1.8 in:
    • Cargo.toml
    • npm/package.json
  • Keeps Rust crate and npm package versions aligned for release flow.

# full setup (config + alias/function install)
v0k setup

# install alias/function only
v0k setup alias

[slhmy]

@copilot bump version

[Copilot]

@copilot bump version

Done. Bumped version from 0.1.7 to 0.1.8 in both Cargo.toml and npm/package.json in commit 15d1957.