Adds a durable receiver-side ledger (BLEPrivateMediaReceiptStore) mapping a deterministic private-media message ID — hash-bound to sender, recipient, and entropy-bearing filename — to the stored file before UI delivery and before the Noise-encrypted delivery ACK, so sender retries and relaunches cannot create duplicate bubbles or files. Receipts are unforgeable without the Noise session; capability bit 9 rides the existing announce bitfield (no wire-format change; rolling upgrade safe both directions).
Includes review fixes: corrupt receipt records are quarantined per-record (bytes preserved at <id>.json.corrupt, only that ID fail-closed — previously one bad record silently disabled ALL inbound private media forever); the panic reset now reaches BLEService's own store instance via completePanicReset with a production-wiring test; and both content.delivery.reason.* strings ship with full 30-locale coverage.
Closes the last cleartext private-content path over BLE: private DM images/voice were sent as plaintext signed fileTransfer packets, TTL-relayed across the mesh, so every relay saw the full bytes. Now the complete BitchatFilePacket is encrypted as a single Noise AEAD message (inner type 0x20, matching Android) and the opaque ciphertext is fragmented. Adds an authenticated in-session capability proof (0x21 TLV: capabilities + Ed25519 key), TOFU-style downgrade pinning, a per-send consent dialog for the signed-cleartext fallback to legacy peers, and a cancellation/admission registry so cancel/delete cannot race a deferred cleartext send.
Android wire constants (0x20 / 0x21 / capability bit 8) confirmed shipping. The 256-fragment preflight cap applies only to the directed fileTransfer migration fallback; encrypted media to capable peers uses the full receiver ceiling.
Rebased over #1428/#1349: identity reads go through BLELocalIdentityStateStore; the session-bound authenticated signing-key check and the announce-path TOFU pin are kept as complementary checks. Full local suite green (1744+197 tests).
