fix: add _i shorthand to internalKeys set

The _i shorthand for _interactive was missing from the internalKeys set,
which could cause it to be incorrectly treated as a template variable.

Author: johnlindquist

src/cli-runner.ts

@@ -315,8 +315,8 @@ export class CliRunner {
     }
 
     // Extract _varname fields from frontmatter and match with --_varname CLI flags
-    // Variables starting with _ are template variables (except internal keys like _interactive, _cwd, _subcommand)
-    const internalKeys = new Set(["_interactive", "_cwd", "_subcommand"]);
+    // Variables starting with _ are template variables (except internal keys)
+    const internalKeys = new Set(["_interactive", "_i", "_cwd", "_subcommand"]);
     const namedVarFields = Object.keys(frontmatter).filter((k) => k.startsWith("_") && !internalKeys.has(k));
     for (const key of namedVarFields) {
       const defaultValue = frontmatter[key];

src/runtime.ts

@@ -325,7 +325,7 @@ export class AgentRuntime {
 
     // Extract _varname fields from frontmatter and match with --_varname CLI flags
     // Variables starting with _ are template variables (except internal keys)
-    const internalKeys = new Set(["_interactive", "_cwd", "_subcommand"]);
+    const internalKeys = new Set(["_interactive", "_i", "_cwd", "_subcommand"]);
     const namedVarFields = Object.keys(frontmatter)
       .filter(key => key.startsWith("_") && !internalKeys.has(key));