Desktop GUI, cross-platform reader detection

- nfc-writer is now a native egui window (Windows, macOS, Linux); the web
  version moves to the nfc-writer-web binary. Both share src/reader.rs and
  src/ndef.rs through the library crate.
- Reader choice no longer depends on the ACR1252U's Windows naming: skip SAM
  slots, prefer contactless names (PICC/Contactless/NFC/CL), then a reader
  with a card present; NFC_READER forces one by name substring.
- ATR via SCardStatus instead of SCardGetAttrib, which macOS lacks.
- Platform-specific "no reader" hints (pcscd/libccid on Linux, ACS driver on
  macOS); Thai fallback font for the GUI from the system fonts.
- Clippy clean for x86_64-pc-windows-msvc, x86_64-unknown-linux-gnu and
  aarch64-apple-darwin; README with per-OS setup and a test matrix.

Cargo.toml

@@ -1,11 +1,25 @@
 [package]
 name = "nfc-writer"
-version = "0.1.0"
+version = "0.2.0"
 edition = "2024"
-description = "Local web page that programs NFC tags (NDEF URL/text) through a PC/SC reader such as the ACS ACR1252U"
+description = "Program NFC tags (NDEF URL/text) through a PC/SC reader such as the ACS ACR1252U: desktop GUI and local web page"
+default-run = "nfc-writer"
+
+[[bin]]
+name = "nfc-writer"
+path = "src/main.rs"
+
+[[bin]]
+name = "nfc-writer-web"
+path = "src/bin/nfc-writer-web.rs"
+
+[profile.release]
+strip = true
+lto = "thin"
 
 [dependencies]
 axum = "0.8"
+eframe = "0.37"
 pcsc = "2"
 serde = { version = "1", features = ["derive"] }
 serde_json = "1"