fix: add Cargo.lock to project template to avoid broken dependencies

By pinning new project's dependencies to specific versions, we avoid
problems like #187 which are caused by changes in the dependencies
(in this case we were using a prerelease version of a dependency which
updated one of its dependencies to edition=2024, but this will also
prevent accidental semver-breaking changes from breaking our builds,
too).

This also adds a justfile that makes it easy to update the lockfile.

cot-cli/src/main.rs

@@ -33,8 +33,13 @@ enum Commands {
         #[arg(long)]
         name: Option<String>,
         /// Use the latest `cot` version from git instead of a published crate
+        /// (conflicts with --cot-path)
         #[arg(long)]
         use_git: bool,
+        /// Use `cot` from the specified path instead of a published crate
+        /// (conflicts with --use-git)
+        #[arg(long)]
+        cot_path: Option<PathBuf>,
     },
     /// Generate migrations for a Cot project
     MakeMigrations {
@@ -67,6 +72,7 @@ fn main() -> anyhow::Result<()> {
             path,
             name,
             use_git,
+            cot_path,
         } => {
             let project_name = match name {
                 None => {
@@ -80,6 +86,8 @@ fn main() -> anyhow::Result<()> {
 
             let cot_source = if use_git {
                 CotSource::Git
+            } else if let Some(path) = &cot_path {
+                CotSource::Path(path)
             } else {
                 CotSource::PublishedCrate
             };

cot-cli/src/new_project.rs

@@ -13,8 +13,9 @@ macro_rules! project_file {
     };
 }
 
-const PROJECT_FILES: [(&str, &str); 9] = [
+const PROJECT_FILES: [(&str, &str); 10] = [
     project_file!("Cargo.toml.template"),
+    project_file!("Cargo.lock.template"),
     project_file!("bacon.toml"),
     project_file!(".gitignore"),
     project_file!("src/main.rs"),
@@ -28,7 +29,6 @@ const PROJECT_FILES: [(&str, &str); 9] = [
 #[derive(Debug, Clone, PartialEq, Eq, Hash)]
 pub enum CotSource<'a> {
     Git,
-    #[allow(dead_code)] // used in integration tests
     Path(&'a Path),
     PublishedCrate,
 }