[Bug] Custom provider models without explicit provider field fail resolveGatewayModelSupportsImages — images offloaded as text

Summary

When a custom model is configured under models.providers.<name>.models[] without an explicit "provider" field on the model entry, resolveGatewayModelSupportsImages fails to find the model in the catalog. This causes gateway to treat the model as text-only and offload all image attachments instead of sending them as inline image blocks.

Root Cause

In session-utils-r05OsxB5.js (compiled), function resolveGatewayModelSupportsImages:

const modelEntry = (await params.loadGatewayModelCatalog()).find((entry) =>
  entry.id === params.model && (!params.provider || entry.provider === params.provider)
);

Model entries from config do not inherit the provider key and the JSON schema (models.providers.*.models.*) has additionalProperties: false, so adding "provider" to a model entry is stripped on gateway restart.

Result:

• entry.provider = undefined
• params.provider = "kimi-coding" (or whatever provider key is)
• undefined === "kimi-coding" → false
• modelEntry = undefined → return false → images offloaded

Reproduction

Config (openclaw.json)

{
  "models": {
    "mode": "replace",
    "providers": {
      "kimi-coding": {
        "baseUrl": "https://agent-gw.kimi.com/coding",
        "apiKey": "sk-...",
        "api": "anthropic-messages",
        "models": [
          {
            "id": "k2p5",
            "name": "k2p5",
            "reasoning": true,
            "input": ["text", "image"],
            "contextWindow": 131072,
            "maxTokens": 32768
          }
        ]
      }
    }
  },
  "agents": {
    "defaults": {
      "model": { "primary": "kimi-coding/k2p5" }
    }
  }
}

Note: models.providers.kimi-coding.models[0] has no "provider" field — and it cannot have one because of schema validation (additionalProperties: false).

Steps

1. Configure provider and model as above
2. Start gateway
3. Send an image attachment via webchat or any inbound channel
4. Gateway logs: Offloaded image for text-only model
5. The model receives text "An image file was uploaded..." instead of an image block

Expected Behavior

Gateway should find the model and recognize it as image-capable, passing the image as an inline image block (Anthropic Messages image content type).

Actual Behavior

Gateway offloads the image because resolveGatewayModelSupportsImages returns false.

Workaround (Local Patch)

Patch resolveGatewayModelSupportsImages in compiled bundle:

- entry.id === params.model && (!params.provider || entry.provider === params.provider)
+ entry.id === params.model && (!params.provider || !entry.provider || entry.provider === params.provider)

This makes the provider check on the entry optional.

Environment

• OpenClaw version: latest compiled bundle
• Provider: kimi-coding via anthropic-messages API
• Model: k2p5 with input: ["text", "image"]

Suggested Fix (Upstream)

Option A: Allow "provider" field in model schema so it can be explicitly set and not stripped.

Option B: Auto-populate entry.provider from the parent provider key when loading the catalog (since the provider key is already known at load time).

Option C: Make the provider comparison in resolveGatewayModelSupportsImages tolerant of missing entry.provider (as in workaround above).