docs: add tag release workflow to AGENTS.md

AGENTS.md

@@ -105,6 +105,73 @@ Implement CRC8-CCITT (poly 0x07) for CRSF frame validation.
 Added unit tests for empty, single-byte, and known-value cases.
 ```
 
+## Tag Releases
+
+Use annotated tags for releases. Write the release notes to a temporary
+file, then use it as the tag message. Do **not** commit the release
+notes file.
+
+Write release notes:
+```sh
+cat > RELEASES.md << 'EOF'
+# Releases
+
+## 0.1.0 (2026-06-15)
+
+Initial release. Windows-only support.
+
+### Library (`celrs`)
+
+- **CRSF protocol**: CRC8/DVB-S2 validation, frame parsing, and frame
+  construction (RC channels, device ping, parameter read/write).
+- **Telemetry decoders**: GPS, battery, link stats, attitude, flight
+  mode, vario, barometric altitude, airspeed, heartbeat, RPM,
+  temperature, voltages, ESC, and more.
+- **Streaming parser**: incremental frame extraction from raw byte
+  streams with CRC validation.
+- **Parameter protocol**: device ping, parameter read/write, and
+  TX power configuration by enumerating ELRS parameters.
+- **Serial port abstraction**: open/close/read/write with baud-rate
+  probing (handles CP210x chips that cannot hit 921600 exactly),
+  port listing, and auto-detection of ELRS-like devices.
+- **Logger**: level-filtering logger (debug/info/warn/error) with
+  a stdout sink.
+
+### Tools
+
+- **`telemetry`**: live dashboard that connects to an ELRS TX module
+  and displays link quality (RSSI, LQ, SNR, power), battery (voltage,
+  current, capacity, percentage), IMU attitude, flight mode, and a
+  frame-type breakdown. Supports auto-detect, `--list`, `--port`,
+  and `--baudrate` options.
+
+### Notes
+
+- Platform support: **Windows only** (via MinGW/MSVC on CMake + Ninja).
+- Built against C23; tested with GCC 14+ and Clang 18+.
+- Dependencies (Unity, CMock) are fetched automatically at configure
+  time. No manual setup required.
+EOF
+```
+
+Create the annotated tag:
+```sh
+git tag -a v0.1.0 -F RELEASES.md
+```
+
+Verify:
+```sh
+git show v0.1.0
+```
+
+Remove the temporary file:
+```sh
+rm RELEASES.md
+```
+
+Release notes follow the same Markdown rules as `AGENTS.md` (80-column
+wrap, no em dashes, etc.). Version format is `v<major>.<minor>.<patch>`.
+
 ## Documentation (Markdown)
 
 - Wrap normal text and lists at **max 80 columns** (for readability in