feat: log Zed binary commit hash at test start

Extracts the ZED_COMMIT_SHA baked into the binary at compile time
and logs it prominently. This is the definitive proof of what source
the binary was built from.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: lukemarsden

crates/external_websocket_sync/e2e-test/run_e2e.sh

@@ -108,14 +108,27 @@ if [ ! -f "$MOCK_SERVER" ]; then
     exit 1
 fi
 
-echo "[setup] Zed binary: $ZED_BINARY"
-echo "[setup]   md5: $(md5sum "$ZED_BINARY" 2>/dev/null | cut -c1-32)"
-echo "[setup]   size: $(stat -c '%s' "$ZED_BINARY" 2>/dev/null) bytes"
-echo "[setup]   mtime: $(stat -c '%y' "$ZED_BINARY" 2>/dev/null | cut -d. -f1)"
-echo "[setup]   ThreadLoadError in source (expected 1): $(strings "$ZED_BINARY" | grep -c 'ThreadLoadError' 2>/dev/null || echo unknown)"
-echo "[setup]   'creating new thread as fallback' present: $(strings "$ZED_BINARY" | grep -c 'creating new thread as fallback' 2>/dev/null || echo unknown)"
-echo "[setup] Mock server: $MOCK_SERVER"
-echo "[setup]   md5: $(md5sum "$MOCK_SERVER" 2>/dev/null | cut -c1-32)"
+echo ""
+echo "============================================"
+echo "  BINARY VERSIONS"
+echo "============================================"
+# Extract the ZED_COMMIT_SHA baked into the binary at compile time (set via
+# .drone.yml: export ZED_COMMIT_SHA=$(git rev-parse HEAD)). This is the
+# definitive proof of what source the binary was built from.
+# The sha is a 40-char hex string embedded as a string literal.
+ZED_BUILT_SHA=$(strings "$ZED_BINARY" 2>/dev/null | grep -oP '(?<=starting zed version [^,]*, sha )[0-9a-f]{40}' || true)
+if [ -z "$ZED_BUILT_SHA" ]; then
+    # Fallback: find any 40-char hex that looks like a git sha
+    ZED_BUILT_SHA=$(strings "$ZED_BINARY" 2>/dev/null | grep -oE '\b[0-9a-f]{40}\b' | head -1 || true)
+fi
+echo "  Zed binary:        $ZED_BINARY"
+echo "  Zed commit SHA:    ${ZED_BUILT_SHA:-NOT BAKED IN (local dev build?)}"
+echo "  Zed md5:           $(md5sum "$ZED_BINARY" 2>/dev/null | cut -c1-32)"
+echo "  Zed size:          $(stat -c '%s' "$ZED_BINARY" 2>/dev/null) bytes"
+echo "  Go test server:    $MOCK_SERVER"
+echo "  Go server md5:     $(md5sum "$MOCK_SERVER" 2>/dev/null | cut -c1-32)"
+echo "============================================"
+echo ""
 
 echo "[setup] Zed binary: $ZED_BINARY"
 echo "[setup] Mock server: $MOCK_SERVER"