security: remove inline decrypt, raw plaintext endpoint, and saveDecryptedFile

- Remove auto-decrypt on asset detail open (no more inline blob URLs in market app)
- Remove "Decrypt & View" button — all viewing goes through dDRM Viewer runtime
- Remove secureViewAsset(), fetchAllPdfPagesParallel(), overlay functions from market
- Remove proceedWithDecrypt() and saveDecryptedFile() — no plaintext saved to filesystem
- Remove /lit/decrypt endpoint (returns 410 Gone) — no raw bytes leave the server
- Remove ElacityAccess.fetchAndDecrypt() client-side decrypt path
- Fix save-to-cloud folders: images→Pictures, docs→Documents, media→Videos
- Only path to view protected content is now: Open → dDRM Viewer → /lit/secure-view
  (server renders to JPEG/PNG, browser receives only pixels, never raw file bytes)

Security model is now: encrypted CID on IPFS → .ddrm.json capsule on local filesystem
→ double-click or Open → dDRM Viewer validates rights via Lit Action → server decrypts
and renders to lossy image → viewer displays with anti-piracy protections

Made-with: Cursor

Author: SashaMIT