add napi binding package for GitHub Packages publishing

Move the napi bridge from fire-pdf into pdf-inspector as `napi/`.
Package name: @firecrawl/pdf-inspector-js, published to GitHub Packages
(npm.pkg.github.com) as a public package on v* tags.

Exposes two functions:
- classifyPdf(buffer) → type, page count, pages needing OCR
- extractTextInRegions(buffer, pageRegions) → per-region text with
  needsOcr quality flag (GID fonts, garbage, encoding issues)

Includes publish workflow that builds linux-x64-gnu + darwin-arm64
binaries and publishes main + platform-specific packages.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

napi/Cargo.toml

@@ -0,0 +1,19 @@
+[package]
+name = "pdf-inspector-napi"
+version = "0.2.0"
+edition = "2021"
+
+[lib]
+crate-type = ["cdylib"]
+
+[dependencies]
+pdf-inspector = { path = ".." }
+napi = { version = "3.0.0", features = ["serde-json"] }
+napi-derive = "3.0.0"
+
+[build-dependencies]
+napi-build = "2"
+
+[profile.release]
+lto = true
+strip = "debuginfo"