Replace ts-morph with tree-sitter for code parsing

ts-morph loaded full TypeScript compiler with node_modules type resolution,
causing OOM on large projects (e.g. ethers.js ABI types). tree-sitter is a
pure syntax parser with zero type resolution overhead.

- Add language registry with pluggable mapper interface (ready for multi-lang)
- Add TS/JS mapper using native tree-sitter + tree-sitter-typescript/javascript
- Rewrite parseCodeFile() to use tree-sitter AST traversal
- Manual relative import resolution via fs.existsSync (no type checker needed)
- Rewrite extractSymbols() in codeblock.ts with tree-sitter
- Remove getProject/resetProject/tsconfig watch from indexer
- Remove tsconfig from project config schema
- Add graphology-types devDep (fixes 19 pre-existing test suite failures)
- Add npm overrides for tree-sitter-typescript peer dep compatibility

Author: prih

package-lock.json

@@ -60,7 +60,9 @@
     "micromatch": "^4.0.8",
     "mime": "^4.1.0",
     "multer": "^2.1.1",
-    "ts-morph": "^27.0.2",
+    "tree-sitter": "^0.25.0",
+    "tree-sitter-javascript": "^0.25.0",
+    "tree-sitter-typescript": "^0.23.2",
     "ws": "^8.19.0",
     "yaml": "^2.8.2",
     "zod": "^4.3.6"
@@ -76,11 +78,17 @@
     "@types/node": "^25.4.0",
     "@types/supertest": "^7.2.0",
     "@types/ws": "^8.18.1",
+    "graphology-types": "^0.24.8",
     "jest": "^30.3.0",
     "supertest": "^7.2.2",
     "ts-jest": "^29.4.6",
     "tsc-alias": "^1.8.16",
     "tsx": "^4.21.0",
     "typescript": "^5.9.3"
+  },
+  "overrides": {
+    "tree-sitter-typescript": {
+      "tree-sitter": "$tree-sitter"
+    }
   }
 }

package.json

@@ -273,7 +273,6 @@ program
         codeExcludePattern:  gc.code.excludePattern ?? project.excludePattern ?? undefined,
         filesExcludePattern: gc.files.excludePattern ?? project.excludePattern ?? undefined,
         chunkDepth:          project.chunkDepth,
-        tsconfig:            project.tsconfig,
         docsModelName:       `${id}:docs`,
         codeModelName:       `${id}:code`,
         filesModelName:      `${id}:files`,