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/media_cleaner.sh

@@ -43,6 +43,24 @@
 # Media profile also removes: *.iso *.lrc
 #
 # ==============================================================================================
+# DESIGN PRINCIPLES
+# ==============================================================================================
+#
+# Pre-Scan Cleanup
+#   Runs before arr cleanup scripts so orphan detection only encounters actual
+#   media files. Scene debris and download artifacts would otherwise appear as
+#   untracked files and inflate false-positive orphan counts.
+#
+# Profile Separation
+#   Anime and media share different cleanup patterns because their content
+#   differs. *.lrc (lyrics) and *.iso belong in media cleanup but not anime.
+#   Separate profiles prevent cross-contamination of rules.
+#
+# Conservative by Default
+#   Only explicitly listed patterns are removed. The script never guesses
+#   at file intent — if a pattern is not in the list, the file is untouched.
+#
+# ==============================================================================================
 # OPERATIONAL SAFEGUARDS
 # ==============================================================================================
 #