feat: add stella-callgraph-node for JavaScript/TypeScript call graph extraction

- Implemented a new tool `stella-callgraph-node` that extracts call graphs from JavaScript/TypeScript projects using Babel AST.
- Added command-line interface with options for JSON output and help.
- Included functionality to analyze project structure, detect functions, and build call graphs.
- Created a package.json file for dependency management.

feat: introduce stella-callgraph-python for Python call graph extraction

- Developed `stella-callgraph-python` to extract call graphs from Python projects using AST analysis.
- Implemented command-line interface with options for JSON output and verbose logging.
- Added framework detection to identify popular web frameworks and their entry points.
- Created an AST analyzer to traverse Python code and extract function definitions and calls.
- Included requirements.txt for project dependencies.

chore: add framework detection for Python projects

- Implemented framework detection logic to identify frameworks like Flask, FastAPI, Django, and others based on project files and import patterns.
- Enhanced the AST analyzer to recognize entry points based on decorators and function definitions.

bench/reachability-benchmark/cases/go/grpc-sql/case.yaml

@@ -0,0 +1,46 @@
+id: "go-grpc-sql:302"
+language: go
+project: grpc-sql
+version: "1.0.0"
+description: "SQL injection sink reachable via gRPC GetUser method"
+entrypoints:
+  - "grpc:UserService.GetUser"
+sinks:
+  - id: "SqlInjection::GetUser"
+    path: "main.(*userServer).GetUser"
+    kind: "custom"
+    location:
+      file: main.go
+      line: 35
+    notes: "database/sql.Query with string concatenation"
+environment:
+  os_image: "golang:1.22-alpine"
+  runtime:
+    go: "1.22"
+  source_date_epoch: 1730000000
+  resource_limits:
+    cpu: "2"
+    memory: "2Gi"
+build:
+  command: "go build -o outputs/app ."
+  source_date_epoch: 1730000000
+  outputs:
+    artifact_path: outputs/app
+    sbom_path: outputs/sbom.cdx.json
+    coverage_path: outputs/coverage.json
+    traces_dir: outputs/traces
+    attestation_path: outputs/attestation.json
+test:
+  command: "go test -v ./..."
+  expected_coverage: []
+  expected_traces: []
+ground_truth:
+  summary: "SQL injection reachable"
+  evidence_files:
+    - "../benchmark/truth/go-grpc-sql.json"
+sandbox:
+  network: loopback
+  privileges: rootless
+redaction:
+  pii: false
+  policy: "benchmark-default/v1"