bake: csr, streaming ssr, serve integration, safer jsvalue functions, &more (#14900)

Co-authored-by: paperdave <paperdave@users.noreply.github.com>
Co-authored-by: Jarred Sumner <jarred@jarredsumner.com>

src/string.zig

@@ -691,6 +691,7 @@ pub const String = extern struct {
         try self.toZigString().format(fmt, opts, writer);
     }
 
+    /// Deprecated: use `fromJS2` to handle errors explicitly
     pub fn fromJS(value: bun.JSC.JSValue, globalObject: *JSC.JSGlobalObject) String {
         JSC.markBinding(@src());
 
@@ -702,6 +703,16 @@ pub const String = extern struct {
         }
     }
 
+    pub fn fromJS2(value: bun.JSC.JSValue, globalObject: *JSC.JSGlobalObject) bun.JSError!String {
+        var out: String = String.dead;
+        if (BunString__fromJS(globalObject, value, &out)) {
+            bun.assert(out.tag != .Dead);
+            return out;
+        } else {
+            return globalObject.jsErrorFromCPP();
+        }
+    }
+
     pub fn fromJSRef(value: bun.JSC.JSValue, globalObject: *JSC.JSGlobalObject) String {
         JSC.markBinding(@src());
 
@@ -1331,6 +1342,11 @@ pub const String = extern struct {
         const width = str.visibleWidth(false);
         return JSC.jsNumber(width);
     }
+
+    // TODO: move ZigString.Slice here
+    /// A UTF-8 encoded slice tied to the lifetime of a `bun.String`
+    /// Must call `.deinit` to release memory
+    pub const Slice = ZigString.Slice;
 };
 
 pub const SliceWithUnderlyingString = struct {