chore(vendor): import pi 1.3.0

Imported as a linear vendor commit so forge rebases do not replay the upstream root tree.

git-subtree-dir: third_party/pi

git-subtree-split: 71023aec1546d6d677a65669c5665c0927ce0dd0

third_party/pi/packages/codemode/src/identifier.ts

@@ -0,0 +1,12 @@
+/**
+ * The identifier a script uses for a tool: characters that are not valid in a JavaScript
+ * identifier become `_`. `mcp__docs__search` stays as is, `my-tool` becomes `my_tool`.
+ */
+export function toCodemodeIdentifier(name: string): string {
+	let identifier = "";
+	for (const char of name) {
+		const valid = identifier === "" ? /^[A-Za-z_$]$/.test(char) : /^[A-Za-z0-9_$]$/.test(char);
+		identifier += valid ? char : "_";
+	}
+	return identifier === "" ? "_" : identifier;
+}