Add board presets, devices --clear, and test/UX fixes

Board presets:
- anvil new --board mega (uno, mega, nano, nano-old, leonardo, micro)
- anvil new --list-boards shows presets with compatible clones
- FQBN and baud rate flow into .anvil.toml via template variables
- Defaults to uno when --board is omitted

Devices --clear:
- anvil devices --clear deletes .anvil.local, reverts to auto-detect

src/commands/devices.rs

@@ -274,6 +274,31 @@ pub fn set_port(port: Option<&str>, project_dir: Option<&str>) -> Result<()> {
 
 // -- Helpers --------------------------------------------------------------
 
+/// Delete .anvil.local from the given project directory.
+pub fn clear_port(project_dir: Option<&str>) -> Result<()> {
+    let project_path = resolve_project_dir(project_dir)?;
+    require_anvil_project(&project_path)?;
+
+    let local_file = project_path.join(".anvil.local");
+    if !local_file.exists() {
+        println!(
+            "{} No .anvil.local file found -- nothing to clear.",
+            "--".bright_black()
+        );
+        return Ok(());
+    }
+
+    fs::remove_file(&local_file)
+        .context("Failed to delete .anvil.local")?;
+
+    println!(
+        "{} Removed .anvil.local -- port will be auto-detected.",
+        "ok".green()
+    );
+
+    Ok(())
+}
+
 fn resolve_project_dir(project_dir: Option<&str>) -> Result<PathBuf> {
     match project_dir {
         Some(dir) => Ok(PathBuf::from(dir)),

src/commands/new.rs

@@ -2,6 +2,7 @@ use anyhow::{Result, bail};
 use colored::*;
 use std::path::PathBuf;
 
+use crate::board::presets::{self, BoardPreset};
 use crate::templates::{TemplateManager, TemplateContext};
 use crate::version::ANVIL_VERSION;
 
@@ -28,7 +29,52 @@ pub fn list_templates() -> Result<()> {
     Ok(())
 }
 
-pub fn create_project(name: &str, template: Option<&str>) -> Result<()> {
+pub fn list_boards() -> Result<()> {
+    println!("{}", "Available board presets:".bright_cyan().bold());
+    println!();
+
+    for preset in presets::PRESETS {
+        let marker = if preset.name == presets::DEFAULT_PRESET {
+            " (default)"
+        } else {
+            ""
+        };
+        println!(
+            "  {}{}",
+            preset.name.bright_white().bold(),
+            marker.bright_cyan()
+        );
+        println!("      {}", preset.description);
+        if !preset.also_known_as.is_empty() {
+            println!("      Also: {}", preset.also_known_as.bright_black());
+        }
+        println!("      FQBN: {}", preset.fqbn.bright_black());
+        println!();
+    }
+
+    println!(
+        "  {}",
+        "Usage: anvil new <project-name> --board mega".bright_yellow()
+    );
+    println!();
+    println!(
+        "  {}",
+        "For boards not listed here, create a project and edit the".bright_black()
+    );
+    println!(
+        "  {}",
+        "fqbn value in .anvil.toml to any valid arduino-cli FQBN.".bright_black()
+    );
+    println!();
+
+    Ok(())
+}
+
+pub fn create_project(
+    name: &str,
+    template: Option<&str>,
+    board: Option<&str>,
+) -> Result<()> {
     // Validate project name
     validate_project_name(name)?;
 
@@ -52,6 +98,25 @@ pub fn create_project(name: &str, template: Option<&str>) -> Result<()> {
         bail!("Invalid template");
     }
 
+    // Resolve board preset
+    let preset: &BoardPreset = match board {
+        Some(b) => {
+            match presets::find_preset(b) {
+                Some(p) => p,
+                None => {
+                    println!(
+                        "{}",
+                        format!("Unknown board preset: '{}'", b).red().bold()
+                    );
+                    println!();
+                    list_boards()?;
+                    bail!("Invalid board preset");
+                }
+            }
+        }
+        None => presets::find_preset(presets::DEFAULT_PRESET).unwrap(),
+    };
+
     println!(
         "{}",
         format!("Creating Arduino project: {}", name)
@@ -59,6 +124,14 @@ pub fn create_project(name: &str, template: Option<&str>) -> Result<()> {
             .bold()
     );
     println!("{}", format!("Template: {}", template_name).bright_cyan());
+    println!(
+        "{}",
+        format!("Board:    {} ({})", preset.name, preset.description).bright_cyan()
+    );
+    println!(
+        "{}",
+        format!("FQBN:     {}", preset.fqbn).bright_black()
+    );
     println!();
 
     // Create project directory
@@ -69,6 +142,8 @@ pub fn create_project(name: &str, template: Option<&str>) -> Result<()> {
     let context = TemplateContext {
         project_name: name.to_string(),
         anvil_version: ANVIL_VERSION.to_string(),
+        fqbn: preset.fqbn.to_string(),
+        baud: preset.baud,
     };
 
     let file_count = TemplateManager::extract(template_name, &project_path, &context)?;

src/commands/refresh.rs

@@ -47,6 +47,8 @@ pub fn run_refresh(project_dir: Option<&str>, force: bool) -> Result<()> {
     let context = TemplateContext {
         project_name: config.project.name.clone(),
         anvil_version: ANVIL_VERSION.to_string(),
+        fqbn: config.build.fqbn.clone(),
+        baud: config.monitor.baud,
     };
 
     // Extract template into a temp directory so we can compare