Document configurable module roots as next phase

AGENTS.md

@@ -190,6 +190,16 @@ Tier 3: parsed 714 files, 714 clean (100.0%), 0 with errors, 0 PsiErrorElements
    optional work remain. `#asm` bodies are intentionally consumed opaquely, so
    nothing inside them has PSI yet.
 
+### Next planned increment
+
+- Add persistent project settings for configurable Jai module/import roots.
+- Use those roots consistently for `#import`/`#load` resolution, completion,
+  symbol navigation, and find-usages.
+- Include configured external `.jai` directories in indexing/search scope so
+  standard-library and custom-module usages are discoverable across files.
+- Add headless tests for settings persistence, custom-root resolution,
+  completion, go-to-definition, and cross-root find-usages.
+
 ### Open questions for the user (unanswered)
 
 Scope (Phases 0–4 vs 0–7), compiler integration, target IDEs, JDK policy. See