Read feature, release workflow (v0.3.0)

- Read button (desktop and web): reads the tag now, bypassing the status
  cache, and puts its first link or text record into the input field so it
  can be copied to another tag. POST /api/read in the web version.
- Raw memory: every 4-byte page from page 0 (UID, lock bytes, CC, data) in
  hex and ASCII, collapsed by default.
- Content now shows the records and the note together (a locked tag showed
  only "read-only" before); read failures are flagged with read_failed
  instead of matching message text.
- .gitea/workflows/release.yml: on a v* tag, tests and clippy, then Linux
  (ubuntu-22.04, glibc 2.35) and Windows (MinGW cross-build) packages
  attached to the tag's release with its CHANGELOG.md section.
- README: reading, why the reader program runs on the reader's machine,
  releases.

Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "nfc-writer"
-version = "0.2.0"
+version = "0.3.0"
 edition = "2024"
 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"