Support public dir (#4783)

* Add optional static_dir support

- add optional application.static_dir field defaulting to none
- copy configured static directory into web output during build/serve
- document config knob and add unit tests
- force full rebuild when static_dir contents change
- sync removes stale outputs and logs copy activity
- track static manifest next to platform dir

Tests: cargo fmt

* default to public dir to match vite

* static_dir -> public_dir

* wip

* deser as none...

* wip... use .manifest.json

* implement dumb form of asset manifest generation

* implement manifest using asset system directly

* cleanup

* dont create extra asset dir for server

---------

Co-authored-by: Evan Almloff <evanalmloff@gmail.com>
Co-authored-by: Jonathan Kelley <jkelleyrtp@gmail.com>

packages/cli/src/serve/runner.rs

@@ -379,6 +379,12 @@ impl AppServer {
                 }
             }
 
+            // If it's in the public dir, we sync it and trigger a full rebuild
+            if self.client.build.path_is_in_public_dir(path) {
+                needs_full_rebuild = true;
+                continue;
+            }
+
             // If it's a rust file, we want to hotreload it using the filemap
             if ext == "rs" {
                 // And grabout the contents
@@ -1028,6 +1034,15 @@ impl AppServer {
         let mut watched_crates = self.local_dependencies(crate_package);
         watched_crates.push(crate_dir);
 
+        // Watch the `public` directory if this is the client crate
+        if self.client.build.crate_package == crate_package {
+            if let Some(public_dir) = self.client.build.user_public_dir() {
+                if public_dir.exists() {
+                    watched_paths.push(public_dir);
+                }
+            }
+        }
+
         // Now, watch all the folders in the crates, but respecting their respective ignore files
         for krate_root in watched_crates {
             // Build the ignore builder for this crate, but with our default ignore list as well