Combine launcher improvements: Homebrew + fish + multi-terminal detection + --here

[DUBSOpenHub]

Combines the best of #1 and #2 without changing the beginner-friendly default.

What's included

From #1 (@djensenius):

• 🍺 Homebrew formula (Formula/agent-pulse.rb) — brew tap DUBSOpenHub/copilot-cli-agent-pulse && brew install agent-pulse
• ⚙️ GitHub Actions release workflow that auto-updates the formula URL + SHA256 on new releases
• 🐟 Fish shell alias support in quickstart.sh
• 🖥️ Multi-terminal-emulator auto-detection in start.sh: Ghostty, iTerm, Kitty, WezTerm, Alacritty, Warp, Terminal.app, tmux, gnome-terminal, xterm

From #2 (@Oregand):

• 🏠 --here flag to run the dashboard in the current terminal (SSH, tmux panes)

What's intentionally excluded

The default-flip from #1 (current-terminal-by-default) — AGENTS.md is explicit about targeting beginners, and the first-run "new window pops up" moment is part of the wow factor. --here (from #2) is the opt-in for power users.

Docs updated

• README.md — Homebrew block, --here docs, auto-detected emulator list, launcher options table
• AGENTS.md — launcher description
• .github/copilot-instructions.md — file map entry
• site/index.html — adds Homebrew line to the install block
• quickstart.sh — fish aliases + new agentpulse-here alias + updated launch hints

Validation

• bash -n start.sh ✅
• bash -n quickstart.sh ✅
• ruby -c Formula/agent-pulse.rb ✅
• YAML lint of release.yml ✅
• ./start.sh --here --export / --version smoke-tested ✅
• Passthrough args reach agent_pulse.py correctly ✅

Supersedes

Closes #1
Closes #2

Credits to @djensenius and @Oregand for the original work.