Project check against the datasheet; fix column parity

The datasheet numbers columns from 1 (Fig. 3: "row 1", "Last pixel
(512 / 256)") and puts odd columns on TVID, so x = 0 (column 1) now
goes to TVID and x = 1 to VID; the encoder had them swapped.

README wiring now lists the J1/J2 pins and power rails from Table 1,
the 5 V buffer, and a pull-down on ENABLE so the panel stays off while
the ESP32 boots without VCLK. encodeRow() documents its T4/T5 margins.
docs/README.md open items are regrouped into done, hardware checks and
software work. main.cpp counts seconds, not frames.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

src/main.cpp

@@ -52,12 +52,12 @@ void setup() {
 
 void loop() {
   static uint32_t last = 0;
-  static uint32_t frames = 0;
+  static uint32_t seconds = 0;
   if (millis() - last >= 1000) {
     last = millis();
     display.fillRect(8, 72, 120, 8, 0);
     display.setCursor(8, 72);
-    display.printf("uptime %lus", (unsigned long)frames++);
+    display.printf("uptime %lus", (unsigned long)seconds++);
     display.display();
   }
 }