feat: add WASM-backed detector path and consolidate release packaging

[dev-pi2pie]

Summary

This PR introduces an optional WASM-backed language detector flow for ambiguous Latin and Han text, exposes a new detector-specific package subpath, and consolidates CI/release packaging around a verified build artifact.

What Changed

• Added a new detector API under @dev-pi2pie/word-counter/detector
• Implemented async detector-aware counting and segmentation entrypoints
• Added a Rust whatlang-based WASM detector crate and build pipeline
• Routed ambiguous und-Latn / und-Hani chunks through the WASM detector when enabled
• Added detector policies, remapping, fallback handling, and section-count support
• Updated CLI/runtime options to support --detector regex|wasm
• Expanded README and package metadata for the new detector entrypoint
• Added package-content verification for published artifacts
• Consolidated release workflows into a prepare + publish pipeline with shared artifacts
• Added CI coverage for build, package verification, detector interop, and package type entrypoints
• Fixed Windows portability issues in the WASM build helper and package typecheck test

Why

• Improves language resolution for ambiguous script-only chunks without changing default behavior
• Keeps the default regex path intact while allowing a higher-fidelity detector mode
• Reduces release workflow duplication and verifies that published artifacts are actually complete
• Improves cross-platform reliability for contributors and CI environments

API / Behavior Notes

• Default detector mode remains regex
• --detector wasm is opt-in
• The detector subpath exposes async APIs such as wordCounterWithDetector
• WASM runtime unavailability is surfaced with an explicit error message
• Short or low-confidence ambiguous chunks still fall back to und-*

Testing

• bun test
• bun run build:wasm
• package type and interop coverage for root and detector entrypoints
• package-content verification for release artifacts

Risks / Follow-ups

• The WASM detector path depends on Rust + wasm-pack during build
• Release/CI now relies on the prepared artifact flow, so future package layout changes should keep verify:package-contents updated