feat(datagrip): migrate from LSP4IJ to native CLI integration

AGENTS.md

@@ -36,7 +36,7 @@ pkg/pgast/         — go-pgquery wrapper: SQL → real PG AST (lint, v2)
 pkg/lint/          — rule engine + rule packs (v2)
 pkg/lsp/           — LSP server (v3)
 editors/vscode/    — VSCode extension (v3)
-editors/datagrip/  — LSP4IJ integration (v4)
+editors/datagrip/  — native JetBrains plugin, shells out to the CLI (v4)
 testdata/corpus/   — real-world .pgsql procedures used as the safety/idempotence harness
 ```
 
@@ -111,8 +111,9 @@ go fmt ./...             # Format Go code
   Per-platform VSIX (`win32/linux/darwin × x64/arm64`) built in CI matrix.
 
 ### V4 — DataGrip
-- `editors/datagrip`: integrate via LSP4IJ (free, works across JetBrains editions incl.
-  DataGrip). No core changes expected.
+- `editors/datagrip`: native JetBrains plugin (no LSP4IJ dependency) that shells out to the
+  `pgtidy` binary directly. Formatting and version info run `pgtidy fmt`/`version`; lint
+  diagnostics and quick-fixes run via a native `ExternalAnnotator` calling `pgtidy lint --json`.
 
 ## Verification
 - **Formatter:** `go test ./...` runs golden-file tests + corpus harness asserting idempotence