Exercise 10 works now, #9 needs to be revised accordingly

exercises/09_GPS_Time/README.md

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+## Exercise 09: GPS Time (L76K)
+
+This exercise boots the T-Beam Supreme and verifies GPS behavior at startup.
+
+Implemented behavior:
+
+1. Initializes PMU, OLED, and SD startup watcher (same startup SD path used in Exercise 08).
+2. Probes GPS at startup for NMEA traffic, module identity, satellite count, and UTC time availability.
+3. If L76K is detected, normal GPS-time flow continues.
+4. If L76K is not detected and Quectel-style module text is detected, OLED shows a hard TODO error:
+   - Quectel detected
+   - L76K required
+   - Quectel support is TODO
+5. Every minute:
+   - If GPS UTC is valid: shows GPS UTC time and satellites on OLED.
+   - If satellites are seen but UTC is not valid yet: shows that condition and RTC time.
+   - If no satellites: shows:
+     - "Unable to acquire"
+     - "satellites"
+     - "Take me outside so I"
+     - "can see satellites"
+     - plus current RTC time.
+
+Notes:
+
+- GPS time displayed is UTC from NMEA RMC with valid status.
+- Satellite count uses best available from GGA/GSV.
+- RTC fallback reads PCF8563 via Wire1.
+
+## Build
+
+```bash
+source /home/jlpoole/rnsenv/bin/activate
+pio run -e node_a
+```
+
+## Upload
+
+```bash
+source /home/jlpoole/rnsenv/bin/activate
+pio run -e node_a -t upload --upload-port /dev/ttyACM0
+```