Switch OpenCode to explicit static/local-aware model selection (#5117)

> **Stacked PR (part 4 of 7).** Depends on:
  - PR #5114
  - PR #5115
  - PR #5116
> Diff against `master` includes commits from earlier PRs in the stack —
the new commit in this PR is the topmost one.

## Thinking Path

> - Paperclip orchestrates AI agents for zero-human companies
> - When creating an OpenCode-local agent, Paperclip currently validates
> `adapterConfig.model` against the *Paperclip host's* `opencode models`
output
> - SSH testing surfaced that this blocks creating an OpenCode agent for
an SSH
> environment: the model that exists on the SSH target isn't visible to
the
> host, so creation fails with "OpenCode requires `adapterConfig.model`
in
> provider/model format" even when the operator picked a real remote
model
> - The initial direction was environment-aware model discovery; the
final
> decision was to keep OpenCode on the same explicit-model pattern as
other
> adapters (default + curated list + manual override) and stop blocking
>   creation on host-side discovery
> - This PR does both: the adapter-models endpoint now accepts
`environmentId` and
> probes against the target environment, and the create-time hard gate
is
> replaced by `requireOpenCodeModelId` which validates `provider/model`
*format*
> without requiring host-local discovery. Test/run-time still surfaces
real
>   auth/availability problems
> - The benefit is that operators can create OpenCode agents for remote
> environments without out-of-band setup, and the model picker in the UI
>   reflects the actually-targeted environment

## What Changed

- Added `requireOpenCodeModelId(input)` in
`opencode-local/src/server/models.ts`,
  exported it from the adapter index
- `ensureOpenCodeModelConfiguredAndAvailable` now delegates the format
check to
  `requireOpenCodeModelId`
- `agentsApi.adapterModels(companyId, adapterType, { environmentId })`
now accepts
  an environment ID and passes it as a query parameter
- `queryKeys.agents.adapterModels` now keys on `(companyId, adapterType,
environmentId)`
- `server/src/routes/agents.ts` reads and validates the new query
parameter,
  forwarding it to the adapter's model probe
- `AgentConfigForm.tsx` and `OnboardingWizard.tsx` build the model query
key from
the currently selected default environment ID and disable autodetect for
  `opencode_local` (model selection is explicit)
- `NewAgent.tsx` simplified — no longer special-cases OpenCode
autodetect
- `company-portability.ts` no longer needs OpenCode-specific autodetect
handling
- Tests added/updated:
  `adapter-model-refresh-routes.test.ts`, `adapter-models.test.ts`,
`agent-permissions-routes.test.ts`,
`opencode-local/src/server/models.test.ts`

## Verification

- `pnpm --filter @paperclipai/server test -- adapter-models
adapter-model-refresh agent-permissions`
- `pnpm --filter @paperclipai/adapter-opencode-local test`
- `pnpm --filter @paperclipai/ui test -- AgentConfigForm
OnboardingWizard NewAgent`
- Manual QA in browser:
1. Boot Paperclip on Tailscale-bound port (so it's reachable from
another
machine), create an OpenCode-local agent, switch the default environment
between two installed sandboxes, and confirm the model list refreshes
     per-environment
  2. Submit with a malformed `provider/model` string and verify the new
     `requireOpenCodeModelId` error surfaces
- Before/after screenshots attached for `AgentConfigForm` model picker

## Risks

- Behavioural shift: switching default environment now triggers a model
refetch.
Should be cheap but introduces a new UI loading state for OpenCode
users.
- Removing dynamic autodetect for OpenCode: if any user configured an
agent
without specifying `model` and relied on autodetect populating it, that
agent
will now fail at submit time. Mitigation: validation error is explicit
and
  actionable.
- New query string parameter on `/api/companies/:id/adapter-models` —
older
clients that omit it still work (parameter is optional and defaults to
null).

## Model Used

- OpenAI GPT-5.4 (reasoning effort: high) via Codex CLI
- Provider: OpenAI
- Used to author the code changes in this PR

## Checklist

- [x] I have included a thinking path that traces from project context
to this change
- [x] I have specified the model used (with version and capability
details)
- [x] I have checked ROADMAP.md and confirmed this PR does not duplicate
planned core work
- [x] I have run tests locally and they pass
- [x] I have added or updated tests where applicable
- [x] If this change affects the UI, I have included before/after
screenshots
- [ ] I have updated relevant documentation to reflect my changes — N/A
- [x] I have considered and documented any risks above
- [x] I will address all Greptile and reviewer comments before
requesting merge

packages/adapters/opencode-local/src/index.ts

@@ -5,6 +5,13 @@ export const label = "OpenCode (local)";
 
 export const DEFAULT_OPENCODE_LOCAL_MODEL = "openai/gpt-5.2-codex";
 
+export function isValidOpenCodeModelId(value: unknown): value is string {
+  if (typeof value !== "string") return false;
+  const trimmed = value.trim();
+  const slashIndex = trimmed.indexOf("/");
+  return Boolean(trimmed) && slashIndex > 0 && slashIndex !== trimmed.length - 1;
+}
+
 export const models: Array<{ id: string; label: string }> = [
   { id: DEFAULT_OPENCODE_LOCAL_MODEL, label: DEFAULT_OPENCODE_LOCAL_MODEL },
   { id: "openai/gpt-5.4", label: "openai/gpt-5.4" },

packages/adapters/opencode-local/src/server/index.ts

@@ -67,6 +67,7 @@ export {
   listOpenCodeModels,
   discoverOpenCodeModels,
   ensureOpenCodeModelConfiguredAndAvailable,
+  requireOpenCodeModelId,
   resetOpenCodeModelsCacheForTests,
 } from "./models.js";
 export { parseOpenCodeJsonl, isOpenCodeUnknownSessionError } from "./parse.js";

packages/adapters/opencode-local/src/server/models.test.ts

@@ -2,6 +2,7 @@ import { afterEach, describe, expect, it } from "vitest";
 import {
   ensureOpenCodeModelConfiguredAndAvailable,
   listOpenCodeModels,
+  requireOpenCodeModelId,
   resetOpenCodeModelsCacheForTests,
 } from "./models.js";
 
@@ -22,6 +23,19 @@ describe("openCode models", () => {
     ).rejects.toThrow("OpenCode requires `adapterConfig.model`");
   });
 
+  it("accepts a provider/model id without running discovery", () => {
+    expect(requireOpenCodeModelId("openai/gpt-5.2-codex")).toBe("openai/gpt-5.2-codex");
+  });
+
+  it("rejects malformed provider/model ids before discovery", () => {
+    expect(() => requireOpenCodeModelId("gpt-5.2-codex")).toThrow(
+      "OpenCode requires `adapterConfig.model`",
+    );
+    expect(() => requireOpenCodeModelId("openai/")).toThrow(
+      "OpenCode requires `adapterConfig.model`",
+    );
+  });
+
   it("rejects when discovery cannot run for configured model", async () => {
     process.env.PAPERCLIP_OPENCODE_COMMAND = "__paperclip_missing_opencode_command__";
     await expect(

packages/adapters/opencode-local/src/server/models.ts

@@ -6,6 +6,7 @@ import {
   ensurePathInEnv,
   runChildProcess,
 } from "@paperclipai/adapter-utils/server-utils";
+import { isValidOpenCodeModelId } from "../index.js";
 
 const MODELS_CACHE_TTL_MS = 60_000;
 const MODELS_DISCOVERY_TIMEOUT_MS = 20_000;
@@ -23,6 +24,14 @@ const discoveryCache = new Map<string, { expiresAt: number; models: AdapterModel
 const VOLATILE_ENV_KEY_PREFIXES = ["PAPERCLIP_", "npm_", "NPM_"] as const;
 const VOLATILE_ENV_KEY_EXACT = new Set(["PWD", "OLDPWD", "SHLVL", "_", "TERM_SESSION_ID", "HOME"]);
 
+export function requireOpenCodeModelId(input: unknown): string {
+  const model = asString(input, "").trim();
+  if (!isValidOpenCodeModelId(model)) {
+    throw new Error("OpenCode requires `adapterConfig.model` in provider/model format.");
+  }
+  return model;
+}
+
 function dedupeModels(models: AdapterModel[]): AdapterModel[] {
   const seen = new Set<string>();
   const deduped: AdapterModel[] = [];
@@ -172,10 +181,7 @@ export async function ensureOpenCodeModelConfiguredAndAvailable(input: {
   cwd?: unknown;
   env?: unknown;
 }): Promise<AdapterModel[]> {
-  const model = asString(input.model, "").trim();
-  if (!model) {
-    throw new Error("OpenCode requires `adapterConfig.model` in provider/model format.");
-  }
+  const model = requireOpenCodeModelId(input.model);
 
   const models = await discoverOpenCodeModelsCached({
     command: input.command,