Add multi-quality variant support for video content:
- New ABR types in pkg/smsg/types.go (ABRManifest, Variant, ABRPresets)
- New pkg/smsg/abr.go with manifest read/write and bandwidth estimation
- New cmd/mkdemo-abr CLI tool for creating ABR variant sets via ffmpeg
- WASM parseABRManifest and selectVariant functions
- Demo page "Adaptive Quality" tab with ABR player
- RFC-001 Section 3.7 documenting ABR format and algorithm
Profile page:
- No WASM or video download until play button clicked
- Play button visible immediately, loading on-demand
- Removed auto-play behavior completely
Streaming:
- GetV3HeaderFromPrefix for parsing from partial data
- v3 demo file with 128KB chunks for streaming tests
V3 streaming format enables zero-trust media streaming:
- Content encrypted once with random CEK
- CEK wrapped with time-bound stream keys derived from LTHN hash
- Rolling window: current period + next period always valid
- Keys auto-expire, no revocation needed
Cadence options (platform controls refresh rate):
- daily: 24-hour periods (2026-01-12)
- 12h: Half-day periods (2026-01-12-AM/PM)
- 6h: Quarter-day periods (2026-01-12-00/06/12/18)
- 1h: Hourly periods (2026-01-12-15)
Key derivation: SHA256(LTHN(period:license:fingerprint))
- LTHN is rainbow-table resistant (salt derived from input)
- Only the derived key can decrypt, never transmitted
New files:
- pkg/smsg/stream.go - v3 encryption/decryption
- pkg/smsg/stream_test.go - 17 tests including cadence
WASM v1.3.0:
- BorgSMSG.decryptV3(data, {license, fingerprint})
- getInfo() now returns cadence and keyMethod
