bug(app): custom models without release dates are hidden in V2 #60479

Description

V2 desktop loads custom models from the global config, but the model picker hides them when no release date is configured. On Windows, the running service returns the provider as enabled and the model with time.released: 0. The app converts that unknown date to 1970-01-01, so its default visibility filter excludes the model.

This reproduces the defect reported in #49605 on the current V2 code; #50726 describes the same desktop symptom.

Steps to reproduce

1. Add a model with no catalog entry or release date to %USERPROFILE%\.config\opencode\opencode.jsonc:

   {
     "providers": {
       "local-example": {
         "name": "Local example",
         "package": "@opencode/ai/providers/openai-compatible",
         "settings": { "baseURL": "http://127.0.0.1:8000/v1" },
         "models": {
           "local-example-model": {
             "name": "Local example model",
             "limit": { "context": 65536, "output": 8192 }
           }
         }
       }
     }
   }

2. Open a client with no saved model visibility preference.
3. Open the model picker and search for local-example-model.

Expected: the enabled model is visible, using the existing unknown-date fallback.
Actual: it is hidden; manually enabling it in Manage models makes it appear.

OpenCode version

Reproduced with fork desktop 2.2.0-dev-my.4; the same normalization and visibility logic remains in upstream dev at cd6551f9a0 and fork 2.2.1-dev-my.1.

Operating System

Windows x64 (shared web/desktop app logic).

Verification

Read-only /api/config, /api/provider, and /api/model requests confirm successful config loading. A regression test against the real catalog adapter fails before preserving released: 0 as an empty date. Known release dates and explicit visibility preferences should retain their behavior.