Remove private review docs from repo, ignore docs/

Move all App Review reply drafts, App Store Connect fill-in sheets,
and Ko-fi copy out of the public repo. They live on the local machine
under ~/Documents/PromptBar-Private/ now.

Add docs/ and review/kofi filename patterns to .gitignore so the same
files never get accidentally committed again.

Author: peterdsp

.gitignore

@@ -1,3 +1,11 @@
+## Private docs (App Store reviews, Ko-fi copy, pricing strategy, etc.)
+## Never commit anything under docs/, keep it on the local machine only.
+docs/
+*_REVIEW_*.md
+*_REVIEW_REPLY.md
+APP_STORE_CONNECT*.md
+KOFI_*.md
+
 # Xcode
 #
 # gitignore contributors: remember to update Global/Xcode.gitignore, Objective-C.gitignore & Swift.gitignore