Resolution dropdown drives the output frame: vertical 9:16 tier with semi-crop preview over the fixed 1920x1080 master

TASKS.md

@@ -162,12 +162,16 @@ Preview shows the transition too (WYSIWYG). No wipes/slides/LUTs beyond the four
 1. **Encoding** — H.264 (hardware via NVENC/AMD, fallback x264) + AAC audio; **must comply**: keyframes ≤ 4s (gopSizeLong), closed GOP, AAC/MP3 @ 44.1/48kHz, mono/stereo only
 2. **RTMP push** — FFmpeg subprocess or native RTMP library, to the cached reusable stream's ingestion URL
 3. **Quality ladder** — the offered tiers, with **1080p60 @ 8 Mbps as the standard/default**:
-   - Phone 480p @ 2.5 Mbps
+   - 720p30 @ 6 Mbps
    - 720p60 @ 6 Mbps
    - 1080p30 @ 8 Mbps
    - **1080p60 @ 8 Mbps** (default — mainstream ceiling, GPU hardware-encoded so the gaming
      machine never notices; upload headroom stays comfortable)
+   - Vertical 1080×1920 @ 60fps @ 8 Mbps (9:16 phone tier)
    - 1440p/4K = the paid unlock tiers (monetization), not the standard offering
+   The composition master is always 1920×1080; a tier is an output rect + target resolution
+   (see `ai.md` "Resolution tiers"). Vertical output = the centered 607×1080 crop of the master
+   scaled to 1080×1920 (semi-crop preview is already implemented; the encoder applies the same rect).
    Ladder is sculpted by a **cached probe** (IP-only TCP vs public ingest host; no auth required).
    Quality is greyed out while live because the declared resolution can't change mid-stream — but
    with `variable`, we can **auto step-down** bitrate/resolution on the fly with zero API calls