Move common primitives to src/common/primitives/

Phase 1 of #5963: reorganize building blocks (buffer, parser, input,
data, and shared utilities) under common/primitives/. Runtime code
(services, public API, CoreTerminal, InputHandler) stays in place.

Update import paths across browser, headless, addons, and tests.
Add TypeScript path mappings so common/* aliases resolve primitives
first, then the common root.

Co-authored-by: Daniel Imms <Tyriar@users.noreply.github.com>

bin/esbuild.mjs

@@ -190,7 +190,10 @@ if (config.addon) {
     ...outConfig,
     entryPoints: [
       'src/browser/**/*.ts',
-      'src/common/**/*.ts',
+      'src/common/primitives/**/*.ts',
+      'src/common/services/**/*.ts',
+      'src/common/public/**/*.ts',
+      'src/common/*.ts',
       'src/headless/**/*.ts'
     ],
     outdir: 'out-esbuild/'