chore: bundle extension with esbuild

CHANGELOG.md

@@ -7,6 +7,9 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## [Unreleased]
 
+### Changed
+- Bundle the extension with esbuild. `out/extension.js` is now a single ~64 KB minified file replacing the per-file `tsc` emit. `npm run compile` and `npm run watch` fan out into parallel typecheck (`tsc --noEmit`) + bundle (`node esbuild.mjs`) processes via `npm-run-all2`, matching the official VS Code extension sample so editor type errors and bundle errors surface side-by-side. `npm run package` runs the production esbuild step before `vsce package`. The published `.vsix` shrinks to 7 files / 35 KB (from a multi-file `out/` emit) and no longer ships uncompiled source. Lays groundwork for adding `fast-xml-parser` as a runtime dep in the upcoming SOAP-mostly migration without breaking the zero-shipped-runtime-deps posture.
+
 ## [0.4.2]
 
 ### Fixed

esbuild.mjs

@@ -0,0 +1,57 @@
+import * as esbuild from 'esbuild';
+
+const production = process.argv.includes('--production');
+const watch = process.argv.includes('--watch');
+
+/**
+ * Plugin that emits build start/end markers and TS-style diagnostics so VS
+ * Code's task runner can pick up errors during watch builds. Mirrors the
+ * pattern in the official vscode-extension-samples esbuild template.
+ */
+const problemMatcherPlugin = {
+    name: 'esbuild-problem-matcher',
+    setup(build) {
+        build.onStart(() => {
+            console.log('[watch] build started');
+        });
+        build.onEnd(result => {
+            for (const { text, location } of result.errors) {
+                console.error(`✘ [ERROR] ${text}`);
+                if (location) {
+                    console.error(`    ${location.file}:${location.line}:${location.column}:`);
+                }
+            }
+            console.log('[watch] build finished');
+        });
+    },
+};
+
+async function main() {
+    const ctx = await esbuild.context({
+        entryPoints: ['src/extension.ts'],
+        bundle: true,
+        format: 'cjs',
+        platform: 'node',
+        target: 'node18',
+        outfile: 'out/extension.js',
+        external: ['vscode'],
+        minify: production,
+        // No sourcemap in prod — keeps the .vsix lean; .vscodeignore excludes
+        // .map files anyway, so a linked map would be a dead reference.
+        sourcemap: !production,
+        sourcesContent: !production,
+        logLevel: 'silent',
+        plugins: [problemMatcherPlugin],
+    });
+    if (watch) {
+        await ctx.watch();
+    } else {
+        await ctx.rebuild();
+        await ctx.dispose();
+    }
+}
+
+main().catch(err => {
+    console.error(err);
+    process.exit(1);
+});