build: setup infrastructure for aria MCP code examples

This commit introduces the infrastructure for embedding code examples within Angular packages, enabling them to be consumed by the Angular CLI's MCP server.

The `@angular/aria` package is the first to adopt this new feature. A new `ng_examples_db` Bazel rule is used to build a SQLite database from markdown files containing code examples. This database is then included in the published npm package.

The `package.json` for `@angular/aria` has been updated with an `angular.examples` field to allow tooling to discover and use the code examples.

Author: clydin

src/aria/BUILD.bazel

@@ -1,7 +1,7 @@
 load("@aspect_bazel_lib//lib:copy_to_directory.bzl", "copy_to_directory")
 load("@npm//:defs.bzl", "npm_link_all_packages")
 load("//src/aria:config.bzl", "ARIA_TARGETS")
-load("//tools:defaults.bzl", "ng_package", "ts_project")
+load("//tools:defaults.bzl", "ng_examples_db", "ng_package", "ts_project")
 
 package(default_visibility = ["//visibility:public"])
 
@@ -16,10 +16,26 @@ ts_project(
     deps = ["//:node_modules/@angular/core"],
 )
 
+ng_examples_db(
+    name = "aria_example_database",
+    srcs = glob(
+        include = [
+            "examples/**/*.md",
+        ],
+        # TODO: Remove this once examples are created. It should never be empty at that point.
+        allow_empty = True,
+    ),
+    out = "resources/code-examples.db",
+    path = "src/aria/examples",
+)
+
 ng_package(
     name = "npm_package",
     package_name = "@angular/aria",
-    srcs = ["package.json"],
+    srcs = [
+        "package.json",
+        "resources/code-examples.db",
+    ],
     nested_packages = select({
         "//:snapshot_adev_assets": [":adev_assets"],
         "//conditions:default": [],

src/aria/package.json

@@ -21,6 +21,12 @@
   "dependencies": {
     "tslib": "^2.3.0"
   },
+  "angular": {
+    "examples": {
+      "format": "sqlite",
+      "path": "./resources/code-examples.db"
+    }
+  },
   "ng-update": {
     "packageGroup": "NG_UPDATE_PACKAGE_GROUP"
   },

tools/defaults.bzl

@@ -5,6 +5,7 @@ load("@aspect_rules_js//npm:defs.bzl", _npm_package = "npm_package")
 load("@devinfra//bazel/http-server:index.bzl", _http_server = "http_server")
 load("@devinfra//bazel/spec-bundling:index.bzl", _spec_bundle = "spec_bundle")
 load("@devinfra//bazel/ts_project:index.bzl", "strict_deps_test")
+load("@rules_angular//src/ng_examples_db:index.bzl", _ng_examples_db = "ng_examples_db")
 load("@rules_angular//src/ng_package:index.bzl", _ng_package = "ng_package")
 load("@rules_angular//src/ng_package/text_replace:index.bzl", _text_replace = "text_replace")
 load("@rules_angular//src/ng_project:index.bzl", _ng_project = "ng_project")
@@ -26,6 +27,7 @@ extract_tokens = _extract_tokens
 ng_web_test_suite = _ng_web_test_suite
 spec_bundle = _spec_bundle
 http_server = _http_server
+ng_examples_db = _ng_examples_db
 
 def sass_binary(sourcemap = False, include_paths = [], **kwargs):
     _sass_binary(