Use platform-agnostic worker interface instead of web-worker dependency

[joao-boechat]

Summary

Replaces the web-worker npm polyfill with a platform-specific worker adapter layer. Each platform (browser, Node.js) now provides its own IWorkerHost and IWorkerSelf implementation, eliminating the third-party dependency while giving the shared code a single, clean interface for worker communication.

What changed

• Removed the web-worker optional dependency and the globalThis.Worker polyfill in node.ts
• Removed setWorkerType / workerType — no longer needed since each adapter handles worker creation internally
• Added src/workers/adapters/ with IWorkerHost (main→worker) and IWorkerSelf (worker→main) interfaces
• Added BrowserWorkerHost and NodeWorkerHost implementations
• Added src/browser.ts entry point (mirrors node.ts)
• Updated package.json exports to use browser.ts for browser builds
• Worker scripts no longer call addEventListener("message", ...) or self.postMessage(...) directly — they use the WorkerSelf global

Architecture

Before: polyfill the browser API into Node

  MAIN THREAD                              WORKER THREAD
  ───────────                              ─────────────

  ╔══════════════╗  ╔══════════════╗
  ║  browser.js  ║  ║   node.js    ║
  ║              ║  ║              ║
  ║ uses native  ║  ║ polyfills    ║
  ║ Worker API   ║  ║ via web-     ║
  ║              ║  ║ worker pkg   ║
  ╚══════╤═══════╝  ╚══════╤═══════╝
         │                 │
         └────────┬────────┘
                  │
                  ▼
  ┌───────────────────────┐    ┌───────────────────────┐
  │   Browser Worker API  │    │   Browser Worker API  │
  │                       │    │                       │
  │  · new Worker(url)    │    │  · self.postMessage() │
  │  · addEventListener() │    │  · addEventListener() │
  │  · postMessage()      │    │                       │
  └───────────┬───────────┘    └───────────┬───────────┘
              │                            │
              ▼                            ▼
      ┌───────────────┐           ┌───────────────┐
      │  Shared code  │◄─messages──│  Shared code  │
      │  (main.ts)    │──messages─►│  (worker.ts)  │
      └───────────────┘           └───────────────┘

• Node polyfilled the browser Worker global using web-worker
• All code used browser-native APIs (addEventListener, self.postMessage)
• workerType toggled between "classic" and "module"

After: each platform provides its own adapter

  MAIN THREAD                              WORKER THREAD
  ───────────                              ─────────────

  ╔══════════════╗  ╔══════════════╗
  ║  browser.ts  ║  ║   node.ts    ║
  ╚══════╤═══════╝  ╚══════╤═══════╝
         │                 │
         ▼                 ▼
  ┌────────────┐    ┌────────────┐         ┌──────────────────┐
  │ Browser    │    │ Node       │ boot-   │ WorkerSelf       │
  │ WorkerHost │    │ WorkerHost │ straps  │                  │
  │            │    │            │────────►│ blob URL (browser)│
  │ wraps      │    │ wraps      │         │ data URL (node)  │
  │ Worker API │    │ worker_    │         │                  │
  │            │    │ threads    │         └────────┬─────────┘
  └─────┬──────┘    └─────┬──────┘                  │
        │                 │                         │
        └────────┬────────┘                         │
                 │                                  │
                 ▼                                  ▼
      ╔═════════════════════╗            ╔═════════════════════╗
      ║   IWorkerHost       ║            ║   IWorkerSelf       ║
      ║                     ║            ║                     ║
      ║  · postMessage()    ║            ║  · postMessage()    ║
      ║  · onMessage()      ║            ║  · onMessage()      ║
      ║  · terminate()      ║            ║                     ║
      ╚══════════╤══════════╝            ╚══════════╤══════════╝
                 │                                  │
                 ▼                                  ▼
         ┌───────────────┐              ┌───────────────┐
         │  Shared code  │◄──messages───│  Shared code  │
         │  (main.ts)    │───messages──►│  (worker.ts)  │
         └───────────────┘              └───────────────┘

• No polyfilling — each platform uses its native worker API behind the adapter
• Shared code only touches IWorkerHost and IWorkerSelf interfaces
• WorkerSelf is bootstrapped into the worker thread via blob URL (browser) or data URL (Node) before the worker script runs

[minestarks]

LGTM! Please test thoroughly (including maybe running multiplatform tests?) before merging