Introduce initial implementation of the vmic CLI with PipeWire integration

- Added `Cargo.toml` to define dependencies and project metadata.
- Implemented core CLI functionality for managing virtual microphones (`create`, `edit`, `delete`, `list`, `route`, and `wipe` commands) using `clap`.
- Integrated `rusqlite` for persistent state storage and `pipewire` to manage PipeWire nodes.
- Ensured graceful handling of feedback loops and system defaults during virtual mic creation and deletion.
- Added error handling via `thiserror` for cleaner error definitions.

src/cli.rs

@@ -0,0 +1,90 @@
+use clap::{Args, Parser, Subcommand};
+use clap_complete::Shell;
+
+/// vmic - create and manage PipeWire virtual microphones.
+#[derive(Parser)]
+#[command(name = "vmic", version, about)]
+pub struct Cli {
+    #[command(subcommand)]
+    pub command: Commands,
+}
+
+#[derive(Subcommand)]
+pub enum Commands {
+    /// Create a new virtual microphone.
+    #[command(visible_alias = "mk", visible_alias = "make")]
+    Create(CreateArgs),
+
+    /// Move app streams and mix a hardware source into a vmic.
+    Route(RouteArgs),
+
+    /// Change loopback and volume settings on a vmic.
+    Edit(EditArgs),
+
+    /// Delete a virtual microphone.
+    #[command(visible_alias = "rm", visible_alias = "remove")]
+    Delete(DeleteArgs),
+
+    /// List all virtual microphones.
+    #[command(visible_alias = "ls")]
+    List,
+
+    /// Tear down every vmic, tracked or not.
+    #[command(visible_alias = "reset")]
+    Wipe,
+
+    /// Generate a shell completion script.
+    Completions { shell: Shell },
+}
+
+#[derive(Args)]
+pub struct CreateArgs {
+    /// Name for the new vmic.
+    pub name: String,
+
+    /// Enable a self-monitor loopback.
+    #[arg(short, long)]
+    pub loopback: bool,
+}
+
+#[derive(Args)]
+pub struct RouteArgs {
+    /// Name of the vmic to route into.
+    pub name: String,
+
+    /// Move matching sink-inputs into this vmic's sink.
+    #[arg(short, long = "input", value_name = "APP[:MEDIA]")]
+    pub inputs: Vec<String>,
+
+    /// Move matching source-outputs off this vmic's source.
+    #[arg(short, long = "output", value_name = "APP[:MEDIA]")]
+    pub outputs: Vec<String>,
+
+    /// Mix a hardware source into the vmic, or "off" to remove it.
+    #[arg(short, long = "source", value_name = "SOURCE|off")]
+    pub source: Option<String>,
+}
+
+#[derive(Args)]
+pub struct EditArgs {
+    /// Name of the vmic to edit.
+    pub name: String,
+
+    /// Enable or disable the self-monitor loopback.
+    #[arg(short, long)]
+    pub loopback: Option<bool>,
+
+    /// Loopback volume: fraction (0.8) or percent (80).
+    #[arg(short, long)]
+    pub volume: Option<f32>,
+
+    /// Mixed-in source volume: fraction (0.8) or percent (80).
+    #[arg(long = "source-volume", visible_alias = "sv")]
+    pub source_volume: Option<f32>,
+}
+
+#[derive(Args)]
+pub struct DeleteArgs {
+    /// Name of the vmic to delete.
+    pub name: String,
+}