feat(typescript): add Neo4j-backed analysis backend (Cypher over codeanalyzer-ts graph)

Add TSNeo4jBackend, a drop-in alternative to the in-memory TSCodeanalyzer that
answers the exact same get_* query surface (call graph, callers/callees, class
hierarchy, call sites, decorators, symbol/method/field lookups, imports/exports/
variables, ...) by running Cypher over a live Neo4j graph instead of walking the
pydantic / NetworkX structures.

The graph is the one codeanalyzer-typescript emits with `--emit neo4j` (schema
schema.neo4j.json). The backend can populate the database for you over Bolt
(running the analyzer with --emit neo4j --neo4j-uri), or query a DB that is
already loaded (build_db=False). Results are re-hydrated into the same
cldk.models.typescript pydantic objects the in-memory backend returns; lossy
fields inherent to the projection (collapsed comments/type-params, aggregated
import edges, the three round-tripped CALLS tag keys) are reconstructed
best-effort and documented inline.

- cldk/analysis/typescript/neo4j/: backend, model reconstruction, Neo4jConnectionConfig.
- TypeScriptAnalysis / CLDK.analysis: optional neo4j_config selects the backend;
  default behavior unchanged.
- pyproject: optional `neo4j` extra for the driver.
- tests: live-DB integration tests (skipped when no Neo4j reachable) mirroring the
  in-memory backend's sample-app expectations, plus no-DB backend-selection unit tests.

Author: rahlk

CHANGELOG.md

@@ -5,6 +5,21 @@ All notable changes to this project will be documented in this file.
 The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
+## [Unreleased]
+
+### Added
+- Neo4j-backed TypeScript analysis backend (`cldk.analysis.typescript.neo4j.TSNeo4jBackend`). It
+  is a drop-in alternative to the in-memory `TSCodeanalyzer`: it answers the **same** `get_*`
+  query surface (call graph, callers/callees, class hierarchy, call sites, decorators, symbol
+  lookups, ...) by running **Cypher over a live Neo4j graph** instead of walking the pydantic /
+  NetworkX structures. The graph is the one `codeanalyzer-typescript` emits with `--emit neo4j`
+  (schema `schema.neo4j.json`); the backend can populate the database for you over Bolt, or query
+  one that is already loaded.
+- `TypeScriptAnalysis` / `CLDK.analysis(language="typescript")` now accept an optional
+  `neo4j_config` (`Neo4jConnectionConfig`) to select the Neo4j backend; without it the in-memory
+  backend is used, unchanged.
+- Optional `neo4j` extra (`pip install cldk[neo4j]`) for the Neo4j Python driver.
+
 ## [v1.0.7] - 2026-02-14
 
 ### Added

cldk/analysis/typescript/neo4j/__init__.py

@@ -0,0 +1,22 @@
+################################################################################
+# Copyright IBM Corporation 2026
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#       http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+################################################################################
+
+"""Neo4j-backed TypeScript analysis backend (Cypher queries over the codeanalyzer-ts graph)."""
+
+from cldk.analysis.typescript.neo4j.config import Neo4jConnectionConfig
+from cldk.analysis.typescript.neo4j.neo4j_backend import TSNeo4jBackend
+
+__all__ = ["TSNeo4jBackend", "Neo4jConnectionConfig"]

cldk/analysis/typescript/neo4j/config.py

@@ -0,0 +1,46 @@
+################################################################################
+# Copyright IBM Corporation 2026
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#       http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+################################################################################
+
+"""Connection settings for the Neo4j-backed TypeScript analysis backend."""
+
+from __future__ import annotations
+
+from dataclasses import dataclass
+
+
+@dataclass
+class Neo4jConnectionConfig:
+    """How :class:`TSNeo4jBackend` reaches (and, optionally, populates) the graph database.
+
+    Attributes:
+        uri: Bolt URI of the Neo4j server (e.g. ``bolt://localhost:7687``).
+        username: Neo4j username.
+        password: Neo4j password.
+        database: Database name (None ⇒ server default).
+        application_name: The ``:Application`` anchor name to scope queries to. Defaults to the
+            analyzed project directory's name (matching ``codeanalyzer-typescript``'s
+            ``--app-name`` default).
+        build_db: If True (default), populate the database from the project on construction by
+            running ``codeanalyzer-typescript --emit neo4j``. Set False to query a DB that is
+            already loaded.
+    """
+
+    uri: str
+    username: str = "neo4j"
+    password: str = "neo4j"
+    database: str | None = None
+    application_name: str | None = None
+    build_db: bool = True