fix: drop remaining feature_flags/rotation leftovers - #35

Summary

Follow-up to #29: the feature_flags → bridge rename and the removal of the 180° input rotation left a few stale references behind. Comments and strings only — no behaviour change.

Changes

• src/bridge.h — include guard DRAW_FEATURE_FLAGS_H → DRAW_BRIDGE_H.
• src/bridge.cpp — header comment no longer points to the old feature_flags.h.
• src/draw.{c,h} — "cropped/rotated input" comments → "cropped input"; the preview toggle is gated on crop only.
• data/locale/ja-JP.ini — preview_input no longer mentions a rotated frame (matches en-US / fr-FR).
• readmes/README_fr.md, readmes/README_jp.md — the input-preview description no longer mentions rotation.

How it was tested

• git grep -i "rotat\|feature_flags\|pivot\|回転" over src/, data/, readmes/ and README.md returns nothing.
• Merges cleanly with the open feat: opt-in remote decklist (load a deck from an HTTP endpoint) #31 and fix: keep the Start/Stop button in sync with the detector state #34.