Move SMS phone bridge from campaign_connector submodule into main repo

Consolidates the Termux SMS server code (previously in a separate
campaign_connector git submodule) into termux-sms/ at repo root.
Updates phone clone commands to use sparse checkout so only the
termux-sms/ directory is downloaded onto the Android device.

Bunker Admin

termux-sms/services/sms-api/log/run

@@ -0,0 +1,8 @@
+#!/data/data/com.termux/files/usr/bin/bash
+#
+# runit log service for sms-api
+# Captures stdout/stderr via svlogd (automatic rotation)
+#
+
+mkdir -p "$HOME/logs/sms-api-sv"
+exec svlogd -tt "$HOME/logs/sms-api-sv"