Add CLI subcommands for WASM tool management

Introduces a new CLI module with subcommands for managing WASM tools:
- `tool install`: Build and install tools from source or .wasm files
- `tool list`: List installed tools with optional verbose output
- `tool remove`: Remove installed tools
- `tool info`: Show detailed tool information including capabilities

The install command supports building from Cargo source directories using
cargo-component, or installing pre-compiled .wasm files directly. It
auto-detects capabilities JSON sidecar files and validates them before
installation.

Co-Authored-By: Claude Opus 4.5 <[email protected]>

src/cli/mod.rs

@@ -0,0 +1,53 @@
+//! CLI command handling.
+//!
+//! Provides subcommands for:
+//! - Running the agent (`run`)
+//! - Managing WASM tools (`tool install`, `tool list`, `tool remove`)
+//! - Managing secrets (`secret set`, `secret list`, `secret remove`)
+
+mod tool;
+
+pub use tool::{ToolCommand, run_tool_command};
+
+use clap::{Parser, Subcommand};
+
+#[derive(Parser, Debug)]
+#[command(name = "near-agent")]
+#[command(about = "LLM-powered autonomous agent for the NEAR AI marketplace")]
+#[command(version)]
+pub struct Cli {
+    #[command(subcommand)]
+    pub command: Option<Command>,
+
+    /// Run in interactive CLI mode only (disable other channels)
+    #[arg(long, global = true)]
+    pub cli_only: bool,
+
+    /// Skip database connection (for testing)
+    #[arg(long, global = true)]
+    pub no_db: bool,
+
+    /// Configuration file path (optional, uses env vars by default)
+    #[arg(short, long, global = true)]
+    pub config: Option<std::path::PathBuf>,
+}
+
+#[derive(Subcommand, Debug)]
+pub enum Command {
+    /// Run the agent (default if no subcommand given)
+    Run,
+
+    /// Manage WASM tools
+    #[command(subcommand)]
+    Tool(ToolCommand),
+    // Future: Secret management
+    // #[command(subcommand)]
+    // Secret(SecretCommand),
+}
+
+impl Cli {
+    /// Check if we should run the agent (default behavior or explicit `run` command).
+    pub fn should_run_agent(&self) -> bool {
+        matches!(self.command, None | Some(Command::Run))
+    }
+}