Adds the Hot Module Replacement runtime layer plus the supporting ESM
resolver hardening and dev-session globals that make hot reload viable on
Android.

* `import.meta.hot`: `data`, `accept`, `dispose`, `prune`, `decline`,
  `invalidate`, `on`/`off`/`send` event surface.
* Dev-session globals (`__nsStartDevSession`, `__nsReloadDevApp`,
  `__nsInvalidateModules`, `__nsRunHmrDispose`, `__nsRunHmrPrune`,
  `__nsHasDeclinedModule`, `__nsKickstartHmrPrefetch`,
  `__nsGetLoadedModuleUrls`, `__nsApplyStyleUpdate`,
  `__nsConfigureDevRuntime`/`__nsConfigureRuntime`,
  `__nsTerminateAllWorkers`).
* Speculative HTTP module prefetch (opt-in) with canonical-key
  normalization so `__ns_hmr__/v<N>` and `__ns_boot__/b<N>` tag prefixes
  share `hot.data` identity across reload cycles.
* ESM resolver hardening in `ModuleInternalCallbacks.cpp` to:
  - Preserve synthetic-namespace identity (`ns-vendor://`, `optional:`,
    `node:`, `blob:`) — these are NOT filesystem paths.
  - Handle HTTP/HTTPS module URLs end-to-end (resolution, fetch,
    canonical-key collapse, dynamic import).
  - Compile `.json` imports into synthetic ES modules.
* Android runtime-dex support for `.extend()` classes created during HMR
  that the static binding generator can't see at build time: runtime DEX
  generation with `$`/`_` inner-class normalization (`DexFactory`),
  dev/HMR class-resolution fallback (`ClassResolver`), and dev-flag /
  `logScriptLoading` plumbing (`AppConfig`, `DevFlags`).