feat: scaffold tuimble TUI mumble client

Core modules: TUI app (textual), mumble protocol client,
audio pipeline (sounddevice + opus), push-to-talk with
kitty protocol / evdev / toggle backends. Config via TOML.

docs/INSTALL.md

@@ -0,0 +1,52 @@
+# Installation
+
+## Prerequisites
+
+### System Libraries
+
+```sh
+# Debian/Ubuntu
+sudo apt install libopus0 libopus-dev portaudio19-dev
+
+# Fedora/RHEL
+sudo dnf install opus opus-devel portaudio-devel
+
+# Arch
+sudo pacman -S opus portaudio
+```
+
+### Python
+
+Python 3.11 or later required.
+
+## Setup
+
+```sh
+git clone <repo-url> ~/git/tuimble
+cd ~/git/tuimble
+make setup
+```
+
+## Verify
+
+```sh
+make test
+tuimble --version
+```
+
+## Optional: evdev PTT
+
+For Linux evdev push-to-talk (physical key detection):
+
+```sh
+pip install tuimble[evdev]
+sudo usermod -aG input $USER
+# Log out and back in for group change
+```
+
+## Symlink
+
+```sh
+ln -sf ~/git/tuimble/.venv/bin/tuimble ~/.local/bin/tuimble
+which tuimble
+```