fix(remote_signer): fix ticket value calculation for capability-constraint pricing

[eliteprox]

What does this pull request do? Explain your changes. (required)

This PR updates the remote signer's ticket value calculation to use capability/model-specific pricing from the gateway, so that accurate price info can be provided to the signer.

The change removes the Type field in favor of PriceInfo.Capability for capability and sets model_id to PriceInfo.Constraint which matches how orchestrators advertise pricing for live-video-to-video

Specific updates (required)

Removes the Type field in favor of PriceInfo.Capability for capability and sets model_id to PriceInfo.Constraint which matches how orchestrators advertise pricing for live-video-to-video

• Gateway now fetches capability/model–scoped OrchestratorInfo (including matching TicketParams) before requesting payments, and sends that alongside the selected PriceInfo to the signer.
• Remote signer trusts the provided OrchestratorInfo/PriceInfo, no longer performs its own GetOrchestratorInfo refresh, and normalizes defaults for capability/constraint.
• Updated RemotePaymentRequest to replace the Type field with PriceInfo which contains pricing for all capabilities. OrchestratorInfo.Capability and PriceInfo.Constraint are used for ticket valuation on lv2v requests, matching how orchestrators advertise pricing for live-video-to-video
• Added a safeguard to always issue at least one ticket in the first payment to avoid zero-balance rejections, and updated Python client helpers to request scoped orchestrator info via capabilities.

How did you test each of these updates (required)

• Tested with on-chain remote signer and orchestrator (excluding -pricePerPixel and -pricePerUnit flag along with this models config:

[
    {
      "currency": "USD",
      "model_id": "noop",
      "pipeline": "live-video-to-video",
      "pixels_per_unit": 995328000000,
      "price_per_unit": 5,
      "warm": true,
      "capacity": 1
    }
]

Does this pull request close any open issues?

Fixes how remote signer calculates ticket value, by ensuring it uses the correct capability/constraint price
Removes unintended requirement that orchestrator have -pricePerPixel and -pricePerPixel flags set

Checklist:

• Read the contribution guide
• make runs successfully
• All tests in ./test.sh pass
• README and other documentation updated
• Pending changelog updated

[eliteprox]

Closing PR as it not needed

• Pricing is encoded into ticketParams, provided by OrchestratorInfo response, can't be modified at any point
• OrchestratorInfo request simply needed the correct capability and model to return the correct ticketparams/price, I had been modifying it on the gateway side before sending to signer, which was incorrect.