Add full banner headers to all scripts across the codebase

Every script now has the established header format: PURPOSE with ─────── separator,
OPERATIONAL MODEL, DESIGN PRINCIPLES, OPERATIONAL SAFEGUARDS, CONFIGURATION, and
RUNTIME MODES — structured with full ====== banner sections throughout.

Orchestrators converted from compact ── inline format to full banners. Stale
emby-fallback and dirty sync references removed from Plugin/user_script_plug-in.sh.

Media/arrs_failed_stalled_recovery.sh

@@ -28,6 +28,24 @@
 #   3. Trigger new search     — finds a different release automatically
 #
 # ==============================================================================================
+# DESIGN PRINCIPLES
+# ==============================================================================================
+#
+# Hands-Free Recovery
+#   The script completes the full recovery cycle autonomously — blocklist, remove,
+#   re-search. No operator decision required. A failed import at midnight resolves
+#   itself before morning without any intervention.
+#
+# Age Gate Before Action
+#   Items newer than ARR_IMPORT_RECOVERY_AGE are skipped. Arrs have their own
+#   retry logic — acting immediately would race against it. The age gate gives
+#   the arr time to self-resolve before this script escalates.
+#
+# Blocklist First
+#   The bad release is blocklisted before removal and re-search. Without this,
+#   the re-search can re-grab the same release that just failed.
+#
+# ==============================================================================================
 # OPERATIONAL SAFEGUARDS
 # ==============================================================================================
 #