adjust and refactor together models costs

[P3il4]

• adjust models pricing according to together docs
• remove deprecated models, add missing models
• adjust image aliases to follow "service:org/model" -> "org/model" + "model" rule
• refactor pricing: 3 pricing units: per-mp, per-image, per-tier (geminis quality)

costkeys example:

"togetherai:black-forest-labs/flux_dot_1-schnell:1MP": {
    "units": 27.262976,
    "cost": 7361003.52,
    "count": 17
},
"togetherai:black-forest-labs/flux_dot_2-dev:per-image": {
    "units": 8,
    "cost": 12320000,
    "count": 8
},
"togetherai:google/gemini-3-pro-image:1K": {
    "units": 24,
    "cost": 321600000,
    "count": 24
},

tested with real key and mock server
testing:

puter.ai.txt2img('sakura trees', options = {
model: "togetherai:google/flash-image-3.1", 
ratio: {w: 8, h: 1}, 
quality: '1K'}).then(img => document.body.appendChild(img))