KV-only file storage and agent plugin 1.2.0

Uploads now use optional FILES_KV with no R2 fallback. The source removes default R2 bindings while preserving /files URLs, upload validation and browser uploads. Workers Free KV quotas reject excess operations rather than charge overages; the actual account plan must be verified before activation.

An offline preparer validates backup sizes and SHA-256 hashes, rejects unsafe paths/overwrites, and limits encoded bulk payloads to80MiB. Existing live R2 objects, public endpoints and storage charges are NOT retired by this source change. Full live inventory, verified export and destination readback must precede explicit deletion approval.

Includes updated setup/content skills and MIT-licensed portable/Claude plugin package.
Installation: https://github.com/maxffarrell/orangeCMS/blob/main/docs/PLUGINS.md
Cost and retirement policy: https://github.com/maxffarrell/orangeCMS/blob/main/docs/COSTS.md

Validation:54unit tests, typecheck, compiled Worker upload/OAuth/D1/KV smoke tests and both configurable-route fixtures. All tests use isolated local provider emulators. No remote storage, billing or plans were changed.