Docs: Homebrew dependency table (sshpass, freerdp, builtins)

docs/INSTALL.md

@@ -4,6 +4,25 @@
 - macOS 14+
 - Xcode 15+ (for GUI runs) or Swift toolchain 5.9+ (for CLI builds)
 
+## Dependencies (via Homebrew)
+One command covers everything optional:
+
+```bash
+brew install sshpass freerdp
+```
+
+| Tool | Purpose | Required? | Install |
+|------|---------|-----------|---------|
+| Xcode Command Line Tools | building (`swift build`, C helper) | build only | `xcode-select --install` |
+| `sshpass` | password auto-login from Keychain (no typing) | optional | `brew install sshpass` |
+| `xfreerdp` (FreeRDP) | native RDP sessions | optional | `brew install freerdp` |
+| `ssh`, `sftp`, `ssh-keyscan`, `ssh-keygen` | SSH core, host-key fingerprints | built into macOS | — |
+| SwiftTerm | terminal emulator | bundled via SPM | — |
+| Microsoft Remote Desktop | RDP fallback without FreeRDP | optional | App Store |
+
+Without `sshpass`: passwords are asked interactively in the terminal tab.
+Without FreeRDP: RDP profiles open Microsoft Remote Desktop instead.
+
 ## Option A: Xcode (recommended for GUI)
 1. `open Package.swift` in `RemminaMac/`
 2. Select target `RemminaMac`, destination `My Mac`
@@ -41,7 +60,7 @@ hdiutil verify dist/RemminaMac-*-macos-arm64.dmg
 
 ## RDP requirements
 ```bash
-# For full RDP support:
+# For full RDP support (see dependency table above):
 brew install freerdp
 which xfreerdp
 # Without FreeRDP: install Microsoft Remote Desktop from the App Store
@@ -52,6 +71,7 @@ which xfreerdp
 brew install sshpass
 # Enables password auto-login from Keychain (no typing).
 # Without sshpass: the password prompt appears inside the terminal tab.
+# Full list: dependencies table in [docs/INSTALL.md](docs/INSTALL.md#dependencies-via-homebrew).
 ```
 
 ## Troubleshooting