fix: pin tree-sitter versions and add npm overrides

Pin exact versions (no ^) to prevent surprise upgrades:
- tree-sitter: "0.22.4" (was "^0.22.4")
- tree-sitter-swift: "0.7.1" (was "^0.7.1")

Add npm overrides to suppress peer dependency warnings from grammar
packages that declare ^0.21.x but work fine with 0.22.4.

Note: tree-sitter-swift 0.6.0 fails to build on current Node (needs
node-gyp + Swift toolchain). 0.7.1 with prebuilt binaries is required
for Swift support to work at all.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

gitnexus/package.json

@@ -66,7 +66,7 @@
     "lru-cache": "^11.0.0",
     "mnemonist": "^0.39.0",
     "pandemonium": "^2.4.0",
-    "tree-sitter": "^0.22.4",
+    "tree-sitter": "0.22.4",
     "tree-sitter-c": "^0.21.0",
     "tree-sitter-c-sharp": "^0.21.0",
     "tree-sitter-cpp": "^0.22.0",
@@ -82,7 +82,7 @@
   },
   "optionalDependencies": {
     "tree-sitter-kotlin": "^0.3.8",
-    "tree-sitter-swift": "^0.7.1"
+    "tree-sitter-swift": "0.7.1"
   },
   "devDependencies": {
     "@types/cli-progress": "^3.11.6",
@@ -98,7 +98,8 @@
   "overrides": {
     "@huggingface/transformers": {
       "onnxruntime-node": "$onnxruntime-node"
-    }
+    },
+    "tree-sitter": "0.22.4"
   },
   "engines": {
     "node": ">=18.0.0"