feat(shell-plugin): add Fish shell plugin port of ZSH plugin

[FabioLissi]

Summary

Adds a complete Fish shell plugin port of the existing ZSH plugin, giving Fish users the same :command shortcuts, fzf-powered completions, and right-prompt integration available to ZSH users today.

Context

Fish is a popular shell with a significant user base, but the Forge shell plugin has only shipped as a ZSH plugin. Fish users who want :command dispatch, @file tab completion, and right-prompt session info currently have no supported path to get there. This PR brings the Fish experience to parity with ZSH by porting all the existing ZSH plugin functionality to native Fish.

The plugin is structured as a Fisher-compatible plugin and is already published and tested at FabioLissi/forge-fish.

Changes

• Added shell-plugin/fish/ alongside the existing shell-plugin/ ZSH plugin
• Ported all 40+ :command handlers to Fish functions
• Implemented @file and :command Tab completion using fzf
• Added right-prompt integration (works alongside starship and other prompt themes)
• Added full tab completion for the forge CLI binary (subcommands, flags)
• Included a README.md covering installation, usage, and plugin structure

Key Implementation Details

Fish doesn't use bindkey or ZLE like ZSH — instead the Enter key is intercepted via fish_user_key_bindings and a custom _forge_accept_line function that checks whether the buffer starts with : before handing control back to Fish. All :command handlers are standalone _forge_action_*.fish functions dispatched by a central router. The right prompt hooks into fish_right_prompt without clobbering any existing right prompt output.

Use Cases

# Send a prompt
: explain what this regex does

# Switch models interactively
:model

# AI-generated commit message
:commit

# Browse conversations with fzf
:conversation

# Pick a file to tag
: review this @<Tab>

Testing

# Install Fisher if needed
curl -sL https://raw.githubusercontent.com/jorgebucaran/fisher/main/functions/fisher.fish | source

# Install the plugin from the fork
fisher install FabioLissi/forge-fish

# Open a new shell and verify :command routing works
: hello forge

# Test Tab completion
# Type : then press Tab — should open fzf command picker
# Type @ then press Tab — should open fzf file picker

Alternatively, clone this repo and manually copy shell-plugin/fish/ into ~/.config/fish/ (completions → completions, conf.d → conf.d, functions → functions).

Links

• Standalone plugin repo (Fisher registry): https://github.com/FabioLissi/forge-fish
• Fisher plugin manager: https://github.com/jorgebucaran/fisher

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[amitksingh1490]

@FabioLissi Let’s continue the discussion on #2779. We’re currently thinking about moving extensions to the community, and we’d love to collaborate with you on that PR.