Project-wise pane configuration in Zellij (flakes-1zlj)

Configure Zellij pane/tab naming to visually identify projects in multi-project sessions.

Design

State Management

• State file: /tmp/zellij-tab-{ZELLIJ_SESSION_NAME} — one line per pane: {PANE_ID}={project_name}
• Session root: Capture $PWD at shell init as ZELLIJ_SESSION_PROJECT — the “home” project for the session
• Project name: Git repo root basename (git rev-parse --show-toplevel | basename), fallback to basename $PWD

Pane Name Behavior

Updated in fish_preexec (command starts) and on PWD change.

Tab Name Behavior

On every PWD change in any pane:

1. Write/update own entry in the state file
2. Read all entries, collect unique project names
3. If only one unique project: rename-tab "{project}" (same as today)
4. If multiple: rename-tab "{project1} | {project2} | ..."

Cleanup

• fish_exit event: Remove own pane entry from state file, rebuild tab name
• Shell init: Prune entries whose pane IDs are no longer in the state file

Tasks

• Add helper to resolve project name (git root basename, fallback to basename PWD)
• Capture session project on shell init ($ZELLIJ_SESSION_PROJECT)
• Implement state file writes (per-pane project tracking)
• Update pane name logic: <project> command format when outside session project
• Update tab name logic: aggregate unique projects from state file
• Add cleanup on fish_exit
• Add stale entry pruning on shell init (simplified: natural overwrite on pane ID reuse)

Summary of Changes

Implemented in modules/home/programs/fish/init/zellij.fish:

• zellij_project_name: resolves git repo root basename, fallback to basename PWD
• ZELLIJ_SESSION_PROJECT: captured at shell init to detect foreign projects
• State file (/tmp/zellij-tab-{SESSION}): per-pane project tracking, scoped by session name
• Pane names: <project> command when in foreign project, just command otherwise
• Tab names: aggregated unique projects in pane order, joined with |
• Cleanup on fish_exit removes pane entry and rebuilds tab name