feat(deploy): repeatable Cloudflare deploy script + make targets

deploy/cloudflare/deploy.sh (build → optional parallel R2 media sync → Pages
deploy); 'make deploy' (frontend-only) / 'make deploy-media'. One-time setup
stays documented in README. Guards against unauth + mis-keyed R2 uploads.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

deploy/cloudflare/r2-put-one.sh

@@ -0,0 +1,25 @@
+#!/usr/bin/env bash
+# Upload ONE file to R2 with the right content-type + immutable cache. Used by
+# deploy.sh's parallel xargs (wrangler has no bulk sync). Reads BUCKET / MEDIA_OUT /
+# WRANGLER from the environment; the single argument is the local file path.
+set -u
+f="$1"
+key="${f#"$MEDIA_OUT"/}"
+# Guard: if the prefix strip didn't fire (e.g. relative path vs absolute MEDIA_OUT),
+# the key would wrongly keep a leading dir → wrong R2 path. Fail loudly, don't ship it.
+if [ "$key" = "$f" ]; then
+  echo "FAIL $f  (key strip failed — MEDIA_OUT='$MEDIA_OUT' is not a prefix; pass absolute paths)"
+  exit 1
+fi
+case "${f##*.}" in
+  mp4) ct=video/mp4 ;;
+  mp3) ct=audio/mpeg ;;
+  json) ct=application/json ;;
+  *) ct=application/octet-stream ;;
+esac
+if "$WRANGLER" r2 object put "$BUCKET/$key" --file "$f" --remote \
+     --content-type "$ct" --cache-control "public, max-age=31536000, immutable" >/dev/null 2>&1; then
+  echo "ok   $key"
+else
+  echo "FAIL $key"
+fi