opencode_go provider: GLM-5.2 / GLM-5.3 / GLM-5.3-flash served by the API but missing from the configured model list

**Describe the bug**

The built-in `opencode_go` provider model list is stale. The static model list only includes `glm-5` and `glm-5.1`, but the provider API (`https://opencode.ai/zen/go/v1/models`) also serves `glm-5.2`, `glm-5.3`, and `glm-5.3-flash`. As a result, those models never appear in Goose's model picker / autocomplete even though they work — e.g. `goose session --provider opencode_go --model glm-5.3` runs successfully when the model is named explicitly.

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**To Reproduce**
1. Configure the OpenCode Go provider (`opencode_go`).
2. Open the model picker / autocomplete for the provider (CLI or UI).
3. Observe that among the GLM models, only `glm-5` and `glm-5.1` are listed.
4. (Control) `goose session --provider opencode_go --model glm-5.3` starts a session successfully, confirming the API serves the model.

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**Expected behavior**

`opencode_go` should list the GLM models the API actually serves — `glm-5.2`, `glm-5.3`, and `glm-5.3-flash` — so they appear in the picker instead of being invisible until typed by hand.

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**Verification evidence** (collected 2026-08-31)

- `GET https://opencode.ai/zen/go/v1/models` returns: `glm-5`, `glm-5.1`, `glm-5.2`, `glm-5.3`, `glm-5.3-flash`.
- models.dev (the upstream source of Goose's canonical catalog) reports for opencode-go: `glm-5.2` / `glm-5.3` / `glm-5.3-flash` each have 1,000,000 context / 131,072 output.
- Goose's canonical registry (`canonical_models.json`) already contains `opencode-go/glm-5.2`, `opencode-go/glm-5.3`, and `opencode-go/glm-5.3-flash` — the data layer is current; only the declarative picker list in `crates/goose-providers/src/declarative/definitions/opencode_go.json` is stale.
- The sibling `opencode_zen.json` definition already lists `glm-5.2`, so `opencode_go` is behind its own counterpart.

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**Please provide the following information**
- **OS & Arch:** Linux x86_64
- **Interface:** CLI
- **Version:** 1.48.0
- **Extensions enabled:** n/a
- **Provider & Model:** OpenCode Go – glm-5.3

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**Additional context**

- A previous attempt to refresh this exact list, PR #11089, was closed unmerged on 2026-08-21 with the request to open a tracked issue on the Goose Issues board first — this issue is filed per that guidance.
- Scope is `opencode_go` only. The separate GLM-5.3 issue for the Z.AI (`zai`) provider is tracked in #11667.

Do not begin implementation until the issue reaches **Ready** on the [Goose Issues board](https://github.com/orgs/aaif-goose/projects/1).