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

ui/src/pages/NewAgent.tsx

@@ -34,6 +34,7 @@ import {
 } from "@paperclipai/adapter-codex-local";
 import { DEFAULT_CURSOR_LOCAL_MODEL } from "@paperclipai/adapter-cursor-local";
 import { DEFAULT_GEMINI_LOCAL_MODEL } from "@paperclipai/adapter-gemini-local";
+import { DEFAULT_OPENCODE_LOCAL_MODEL, isValidOpenCodeModelId } from "@paperclipai/adapter-opencode-local";
 
 function createValuesForAdapterType(
   adapterType: CreateConfigValues["adapterType"],
@@ -49,7 +50,7 @@ function createValuesForAdapterType(
   } else if (adapterType === "cursor") {
     nextValues.model = DEFAULT_CURSOR_LOCAL_MODEL;
   } else if (adapterType === "opencode_local") {
-    nextValues.model = "";
+    nextValues.model = DEFAULT_OPENCODE_LOCAL_MODEL;
   }
   return nextValues;
 }
@@ -86,19 +87,6 @@ export function NewAgent() {
     enabled: !!selectedCompanyId,
   });
 
-  const {
-    data: adapterModels,
-    error: adapterModelsError,
-    isLoading: adapterModelsLoading,
-    isFetching: adapterModelsFetching,
-  } = useQuery({
-    queryKey: selectedCompanyId
-      ? queryKeys.agents.adapterModels(selectedCompanyId, configValues.adapterType)
-      : ["agents", "none", "adapter-models", configValues.adapterType],
-    queryFn: () => agentsApi.adapterModels(selectedCompanyId!, configValues.adapterType),
-    enabled: Boolean(selectedCompanyId),
-  });
-
   const { data: companySkills } = useQuery({
     queryKey: queryKeys.companySkills.list(selectedCompanyId ?? ""),
     queryFn: () => companySkillsApi.list(selectedCompanyId!),
@@ -154,32 +142,10 @@ export function NewAgent() {
     if (!selectedCompanyId || !name.trim()) return;
     setFormError(null);
     if (configValues.adapterType === "opencode_local") {
-      const selectedModel = configValues.model.trim();
-      if (!selectedModel) {
+      if (!isValidOpenCodeModelId(configValues.model)) {
         setFormError("OpenCode requires an explicit model in provider/model format.");
         return;
       }
-      if (adapterModelsError) {
-        setFormError(
-          adapterModelsError instanceof Error
-            ? adapterModelsError.message
-            : "Failed to load OpenCode models.",
-        );
-        return;
-      }
-      if (adapterModelsLoading || adapterModelsFetching) {
-        setFormError("OpenCode models are still loading. Please wait and try again.");
-        return;
-      }
-      const discovered = adapterModels ?? [];
-      if (!discovered.some((entry) => entry.id === selectedModel)) {
-        setFormError(
-          discovered.length === 0
-            ? "No OpenCode models discovered. Run `opencode models` and authenticate providers."
-            : `Configured OpenCode model is unavailable: ${selectedModel}`,
-        );
-        return;
-      }
     }
     createAgent.mutate(
       buildNewAgentHirePayload({
@@ -295,7 +261,6 @@ export function NewAgent() {
           mode="create"
           values={configValues}
           onChange={(patch) => setConfigValues((prev) => ({ ...prev, ...patch }))}
-          adapterModels={adapterModels}
           onTestActionChange={handleTestAgentActionChange}
           onTestActionStateChange={handleTestAgentStateChange}
           onTestFeedbackChange={handleTestAgentFeedbackChange}