What problem does it solve? Flutter projects using drift, freezed, json_serializable, and riverpod_generator fail analysis with phantom "missing part file" and undefined-class errors whenever generated *.g.dart, *.freezed.dart, or *.drift.dart files are missing or stale after a clone, branch switch, or source edit. ## Core Features & Use Cases - Pinned one-shot codegen command: Runs dart run build_runner build --delete-conflicting-outputs verbatim, always before flutter analyze, clearing stale-output collisions. - Strict guardrails: Never hand-edit generated files, never force-add them to git, and never use build_runner watch in CI or pre-commit hooks. - Multi-package handling: Explains workspace-root versus per-package regeneration and when to use a fan-out wrapper like melos run gen. - Use Case: After switching branches, the analyzer reports undefined freezed classes; run the pinned build_runner command first, then analyze, and the phantom errors disappear. ## Quick Start Regenerate all Dart codegen output with the pinned build_runner build command and then run flutter analyze on my project.