docs: fix pre-merge audit gaps (missing boards, Ext. KB row)

Full documentation audit before merging 1.26 into main turned up:
- README's Supported Devices table was missing GAT562 Mesh Watch13
  (a CI-built, shipping firmware with zero end-user docs -- pre-existing
  gap, not introduced by this branch) and ProMicro (added to the build
  table by an earlier commit but never to the device list up top).
  Building-from-source's env table was also missing Watch13.
- settings_screen.md's Keyboard table never documented the Ext. KB
  (Full/Compact) setting, despite external_keyboard.md already
  describing it in detail.
- nrf52_power_management.md's board-support table only listed 5 of the
  13 boards that actually have a PowerMgtConfig implementation wired up
  (grep-verified against every variants/*/*.cpp defining `power_config`)
  -- added the other 8, and fixed one board's listed name (RAK 3401,
  not "RAK WisMesh Tag") to match its actual getManufacturerName().

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

docs/nrf52_power_management.md

@@ -40,12 +40,19 @@ Shutdown reason codes (stored in GPREGRET2):
 | Seeed Studio XIAO nRF52840 (`xiao_nrf52`) | Yes         | Yes         | Yes       |
 | RAK4631 (`rak4631`)                       | Yes         | Yes         | Yes       |
 | Heltec T114 (`heltec_t114`)               | Yes         | Yes         | Yes       |
+| Heltec T1 (`heltec_t1`)                   | Yes         | Yes         | Yes       |
+| Heltec T096 (`heltec_t096`)               | Yes         | Yes         | Yes       |
+| Heltec Tower V2 (`heltec_tower_v2`)       | Yes         | Yes         | Yes       |
+| GAT562 30S Mesh Kit (`gat562_30s_mesh_kit`) | Yes       | Yes         | Yes       |
 | GAT562 Mesh Watch13                       | Yes         | Yes         | Yes       |
+| GAT562 Mesh Tracker Pro (`gat562_mesh_tracker_pro`) | Yes | Yes       | Yes       |
+| GAT562 EVB Pro (`gat562_mesh_evb_pro`)    | Yes         | Yes         | Yes       |
+| muzi works R1 Neo (`muziworks_r1_neo`)    | Yes         | Yes         | Yes       |
+| SenseCAP Solar                            | Yes         | Yes         | Yes       |
+| RAK 3401 (`rak3401`)                      | Yes         | Yes         | Yes       |
 | Promicro nRF52840                         | No          | No          | No        |
-| RAK WisMesh Tag                           | No          | No          | No        |
 | Heltec Mesh Solar                         | No          | No          | No        |
 | LilyGo T-Echo / T-Echo Lite               | No          | No          | No        |
-| SenseCAP Solar                            | Yes         | Yes         | Yes       |
 | WIO Tracker L1 / L1 E-Ink                 | No          | No          | No        |
 | WIO WM1110                                | No          | No          | No        |
 | Mesh Pocket                               | No          | No          | No        |

docs/solo_features/settings_screen/settings_screen.md

@@ -104,6 +104,7 @@ The **repeater** mode and its flood filters live on their own screen — see **T
 | Layout   | ABC / T9   | On-screen keyboard style. **ABC**: a-b-c…z grid, one key per letter. **T9**: phone-keypad multi-tap — each key labelled digit+letters (e.g. `2abc`); repeated **Enter** cycles the letters then the digit. Applies to whichever script page is active, not just Latin. |
 | Main | Latin / Cyrillic / Greek | Which script the keyboard opens on by default. **Latin** is the default; picking **Cyrillic** or **Greek** makes that the one you land on, with Latin moving to the Additional cycle instead. |
 | Additional | Latin / Cyrillic / Greek | The second script in the **#@/abc** key's cycle (Main → Additional → Symbols → Main). Setting it to the same script as Main drops the cycle to just that script plus Symbols. **Greek** covers the 24-letter alphabet plus final sigma (`ς`), not the tonos stress accents. Every script renders natively via one shared Unicode font — no separate toggle needed. |
+| Ext. KB | Full / Compact | Only shown on a build with CardKB support (`CARDKB_I2C` or `ENV_PIN_SDA`/`ENV_PIN_SCL` set). Picks how the on-screen keyboard behaves while a CardKB is doing the typing — see [External Keyboard & Joystick](../external_keyboard.md#ext-kb--full-vs-compact). |
 
 Applies to every on-screen text field (messages, waypoint labels, room passwords, preset names). Earlier releases labelled the grid *QWERTY*; the layout has always been alphabetical, so it is now named **ABC**.