Revert to pure userspace; fix chordal hold thumb keys and add layer-tap override

- Remove qmk_firmware submodule, restore CI to build against external Keebart repo
- Fix chordal_hold_layout: thumbs marked 'L'/'R' (not '*') so same-hand
  fast typing resolves as tap, cross-hand resolves as hold
- Add get_chordal_hold() override: layer-taps always hold (for same-hand
  layer access), mod-taps use default cross-hand logic
- Simplify README back to standard userspace overlay

Agent-Logs-Url: https://github.com/timfee/qmk_userspace/sessions/2bf6f380-de28-4523-a92b-40d4f1aa2c25

Co-authored-by: timfee <3246342+timfee@users.noreply.github.com>

.github/workflows/build_binaries.yaml

@@ -9,8 +9,9 @@ jobs:
   build:
     name: 'QMK Userspace Build'
     uses: qmk/.github/.github/workflows/qmk_userspace_build.yml@main
-    # Firmware lives in qmk_firmware/ submodule — no external repo needed.
-    # The reusable workflow detects the submodule and skips its own clone.
+    with:
+      qmk_repo: Keebart/vial-qmk-corne-choc-pro
+      qmk_ref: vial
 
   publish:
     name: 'QMK Userspace Publish'

.gitmodules

@@ -1,4 +0,0 @@
-[submodule "qmk_firmware"]
-	path = qmk_firmware
-	url = https://github.com/Keebart/vial-qmk-corne-choc-pro.git
-	branch = vial

README.md

@@ -1,14 +1,7 @@
 # QMK Userspace — Keebart Corne Choc Pro
 
-Self-contained repo: firmware (Keebart's QMK fork) is embedded as a submodule at `qmk_firmware/`.
-No waiting on upstream — cherry-pick, merge, or patch anything you want right here.
-
-## Quick start
-
-```bash
-git clone --recursive https://github.com/timfee/qmk_userspace.git
-cd qmk_userspace
-```
+QMK userspace overlay for the Keebart Corne Choc Pro. Builds against
+[Keebart/vial-qmk-corne-choc-pro](https://github.com/Keebart/vial-qmk-corne-choc-pro) (vial branch).
 
 GitHub Actions builds the `.uf2` automatically on push — download from the **Releases** tab.
 
@@ -18,54 +11,6 @@ Flash: hold **Q** while plugging in the left half, drag `.uf2` onto `RPI-RP2`. R
 
 ```bash
 pip install qmk
-qmk setup -H qmk_firmware   # point QMK at the submodule
+qmk setup -H . --home $(pwd)/qmk_firmware
 qmk compile -kb keebart/corne_choc_pro/standard -km timfee
 ```
-
-## Pulling upstream changes
-
-The submodule tracks the `vial` branch of `Keebart/vial-qmk-corne-choc-pro`.
-
-```bash
-# Pull latest from Keebart
-cd qmk_firmware
-git fetch origin
-git merge origin/vial        # or: git rebase origin/vial
-cd ..
-git add qmk_firmware
-git commit -m "Update firmware submodule"
-```
-
-### Cherry-picking from other repos (e.g. Keebart/vial-qmk-keebart, qmk/qmk_firmware)
-
-```bash
-cd qmk_firmware
-
-# Add any upstream remote once
-git remote add upstream-qmk https://github.com/qmk/qmk_firmware.git
-git remote add keebart-full https://github.com/Keebart/vial-qmk-keebart.git
-
-# Fetch and cherry-pick
-git fetch keebart-full
-git cherry-pick <commit-sha>   # e.g. OLED SSD1312 support
-
-cd ..
-git add qmk_firmware
-git commit -m "Cherry-pick: <description>"
-```
-
-### Switching to your own firmware fork
-
-If you fork `Keebart/vial-qmk-corne-choc-pro` to your own GitHub account:
-
-```bash
-cd qmk_firmware
-git remote set-url origin https://github.com/YOUR_USER/vial-qmk-corne-choc-pro.git
-git push origin vial          # push your changes to your fork
-cd ..
-# Update .gitmodules to point at your fork
-git config -f .gitmodules submodule.qmk_firmware.url \
-  https://github.com/YOUR_USER/vial-qmk-corne-choc-pro.git
-git add .gitmodules qmk_firmware
-git commit -m "Point submodule at my firmware fork"
-```

qmk_firmware

@@ -1 +0,0 @@
-Subproject commit 4649f864f15ba9f540ee83d66b50cb9fcd4f7e59

users/timfee/timfee.c

@@ -7,7 +7,10 @@
 
 // ── Chordal Hold layout ──
 // Defines hand assignments for the "opposite hands" tap-hold rule.
-// 'L' = left hand, 'R' = right hand, '*' = either (thumb keys).
+// 'L' = left hand, 'R' = right hand.
+// Thumbs are assigned to their physical hand so that same-hand fast
+// typing (e.g. backspace → A) resolves as tap, while cross-hand
+// shortcuts (e.g. left-thumb CMD + right-hand key) resolve as hold.
 // Matrix: 8 rows × 7 cols (4 rows per half, split keyboard).
 //   Rows 0-2: left finger rows    Rows 4-6: right finger rows
 //   Row 3:    left thumb           Row 7:    right thumb
@@ -15,13 +18,25 @@ const char chordal_hold_layout[MATRIX_ROWS][MATRIX_COLS] PROGMEM = {
     {'L', 'L', 'L', 'L', 'L', 'L', 'L'},  // row 0: left top
     {'L', 'L', 'L', 'L', 'L', 'L', 'L'},  // row 1: left mid
     {'L', 'L', 'L', 'L', 'L', 'L',  0 },  // row 2: left bot
-    { 0,   0,   0,  '*', '*', '*',  0  },  // row 3: left thumb
+    { 0,   0,   0,  'L', 'L', 'L',  0 },  // row 3: left thumb
     {'R', 'R', 'R', 'R', 'R', 'R', 'R'},  // row 4: right top
     {'R', 'R', 'R', 'R', 'R', 'R', 'R'},  // row 5: right mid
     {'R', 'R', 'R', 'R', 'R', 'R',  0 },  // row 6: right bot
-    { 0,   0,   0,  '*', '*', '*',  0  },  // row 7: right thumb
+    { 0,   0,   0,  'R', 'R', 'R',  0 },  // row 7: right thumb
 };
 
+// ── Chordal Hold per-key override ──
+// Layer-tap keys (ESC_L2, MIN_L1) must always resolve as hold when
+// another key is pressed so the layer activates — even for same-hand keys.
+// Mod-tap keys use the default layout-based logic (cross-hand = hold).
+bool get_chordal_hold(uint16_t tap_hold_keycode, keyrecord_t *tap_hold_record,
+                      uint16_t other_keycode, keyrecord_t *other_record) {
+    if (IS_QK_LAYER_TAP(tap_hold_keycode)) {
+        return true;
+    }
+    return get_chordal_hold_default(tap_hold_record, other_record);
+}
+
 // ── Combos (matching Vial config) ──
 const uint16_t PROGMEM lparen_combo[] = {KC_R, KC_T, COMBO_END};
 const uint16_t PROGMEM rparen_combo[] = {KC_Y, KC_U, COMBO_END};