Add ESC key overrides: Ctrl→` and Shift→~

Replace QK_GESC with KC_ESC and use the Key Overrides feature to send
backtick on Ctrl+ESC and tilde on Shift+ESC.

CLAUDE.md

@@ -0,0 +1,25 @@
+# QMK Keyboard Configuration
+
+## MANDATORY: Documentation First
+
+Before editing ANY QMK configuration file, you MUST:
+1. Fetch the relevant page from https://docs.qmk.fm to verify current API, functions, and macros
+2. Never invent or guess function names — always confirm they exist in the official docs
+3. If unsure whether a feature/function exists, check docs.qmk.fm before writing any code
+
+## Key documentation pages to check (by task):
+- Keycodes: https://docs.qmk.fm/keycodes
+- Layers: https://docs.qmk.fm/feature_layers
+- Macros: https://docs.qmk.fm/feature_macros
+- Tap Dance: https://docs.qmk.fm/feature_tap_dance
+- Combos: https://docs.qmk.fm/feature_combo
+- Custom shifts: https://docs.qmk.fm/feature_key_overrides
+- config.h options: https://docs.qmk.fm/config_options
+
+## Rules
+- Always use the exact function signatures from docs.qmk.fm
+- Do not use functions from memory if they can be verified online
+- If a docs page contradicts your training data, trust the docs page
+
+## Git
+- Never mention Claude or Claude Code as author or co-author in commit messages

keyboards/tweetydabird/lotus58/keymaps/lotus/keymap.c

@@ -2,6 +2,15 @@
 // SPDX-License-Identifier: GPL-2.0-or-later
 #include QMK_KEYBOARD_H
 
+const key_override_t ctrl_esc_override  = ko_make_basic(MOD_MASK_CTRL, KC_ESC, KC_GRV);
+const key_override_t shift_esc_override = ko_make_basic(MOD_MASK_SHIFT, KC_ESC, S(KC_GRV));
+
+const key_override_t *key_overrides[] = {
+    &ctrl_esc_override,
+    &shift_esc_override,
+    NULL
+};
+
 // Define custom keycodes
 enum custom_keycodes {
     // F19 on tap, Hyper (Cmd+Ctrl+Opt+Shift) on hold
@@ -10,7 +19,7 @@ enum custom_keycodes {
 
 const uint16_t PROGMEM keymaps[][MATRIX_ROWS][MATRIX_COLS] = {
     [0] = LAYOUT(
-        QK_GESC,   KC_1,    KC_2,    KC_3,    KC_4,    KC_5,    KC_MPLY,        KC_MPLY, KC_6,    KC_7,     KC_8,    KC_9,    KC_0,    KC_MINS,
+        KC_ESC,   KC_1,    KC_2,    KC_3,    KC_4,    KC_5,    KC_MPLY,        KC_MPLY, KC_6,    KC_7,     KC_8,    KC_9,    KC_0,    KC_MINS,
         KC_TAB,    KC_Q,    KC_W,    KC_E,    KC_R,    KC_T,                             KC_Y,    KC_U,     KC_I,    KC_O,    KC_P,    KC_LBRC,
         HYPER_F19, KC_A,    KC_S,    KC_D,    KC_F,    KC_G,                             KC_H,    KC_J,     KC_K,    KC_L,    KC_SCLN, KC_QUOT,
         KC_LSFT,   KC_Z,    KC_X,    KC_C,    KC_V,    KC_B, TG(1),             KC_9,    KC_N,    KC_M,     KC_COMM, KC_DOT,  KC_SLSH, RSFT_T(KC_BSLS),

keyboards/tweetydabird/lotus58/keymaps/lotus/rules.mk

@@ -1,6 +1,7 @@
 CONVERT_TO=rp2040_ce
 
 ENCODER_MAP_ENABLE = yes
+KEY_OVERRIDE_ENABLE = yes
 AUTO_SHIFT_ENABLE = no
 
 # CAPS_WORD_ENABLE = yes