[codex] Add Claude model refresh (#6953)

## Thinking Path

> - Paperclip orchestrates AI-agent companies through adapter-backed
local and external runtimes.
> - The agent configuration UI lets operators choose adapter models and
refresh model lists when adapters support live discovery.
> - Codex already had a live refresh path, but Claude Local only exposed
static fallback models and the UI hid the refresh action for Claude.
> - A newly available Claude Opus model should not require a code
release every time the model catalog changes.
> - This pull request adds Anthropic model discovery for Claude Local,
keeps the static fallback current with Claude Opus 4.8, and exposes the
existing refresh button in the Claude Local dropdown.
> - The benefit is that operators can refresh Claude models from the
same model selector flow they already use for Codex.

## What Changed

- Added `claude-opus-4-8` to the Claude Local fallback model list.
- Added Claude model discovery through Anthropic-compatible `GET
/v1/models` when `ANTHROPIC_API_KEY` is available.
- Added normal cache reuse, forced refresh support, a SHA-256-based
API-key fingerprint for cache keys, and warning logging for discovery
errors before fallback.
- Wired `claude_local.refreshModels` into the server adapter registry.
- Enabled the existing `Refresh models` dropdown action for
`claude_local` in `AgentConfigForm`.
- Added tests for Claude fallback, live discovery, API-failure fallback,
forced refresh, and the UI refresh-button gate.

## Verification

- `pnpm exec vitest run server/src/__tests__/adapter-models.test.ts`
- `pnpm exec vitest run ui/src/components/AgentConfigForm.test.ts`
- `pnpm --filter @paperclipai/adapter-claude-local typecheck`
- `pnpm --filter @paperclipai/server typecheck`
- `pnpm --filter @paperclipai/ui typecheck`
- Greptile review reached Confidence Score: 5/5 on commit `b796cf4f1`
with addressed threads resolved.

UI note: the visible change is a conditional action row inside the
existing model dropdown; the regression test covers that `claude_local`
now receives the refresh action.

## Risks

- Low risk. Without `ANTHROPIC_API_KEY`, Claude Local still uses the
static fallback list.
- If Anthropic model discovery fails or times out, Paperclip falls back
to the existing cached or static list.
- Bedrock environments remain on Bedrock-native model IDs.

## Model Used

OpenAI GPT-5 via Codex local coding agent, with repository file access,
shell command execution, git operations, and targeted test/typecheck
verification. Exact context window is not exposed by the runtime.

## 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
- [x] I have updated relevant documentation to reflect my changes
- [x] I have considered and documented any risks above
- [x] I will address all Greptile and reviewer comments before
requesting merge

ui/src/components/AgentConfigForm.test.ts

@@ -0,0 +1,15 @@
+import { describe, expect, it } from "vitest";
+import { supportsAdapterModelRefresh } from "./AgentConfigForm";
+
+describe("supportsAdapterModelRefresh", () => {
+  it("enables the model refresh action for Claude, Codex, and ACPX adapters", () => {
+    expect(supportsAdapterModelRefresh("claude_local")).toBe(true);
+    expect(supportsAdapterModelRefresh("codex_local")).toBe(true);
+    expect(supportsAdapterModelRefresh("acpx_local")).toBe(true);
+  });
+
+  it("keeps the refresh action hidden for adapters without a live refresh hook", () => {
+    expect(supportsAdapterModelRefresh("opencode_local")).toBe(false);
+    expect(supportsAdapterModelRefresh("process")).toBe(false);
+  });
+});

ui/src/components/AgentConfigForm.tsx

@@ -114,6 +114,10 @@ const emptyOverlay: AgentConfigOverlay = {
 /** Stable empty object used as fallback for missing env config to avoid new-object-per-render. */
 const EMPTY_ENV: Record<string, EnvBinding> = {};
 
+export function supportsAdapterModelRefresh(adapterType: string): boolean {
+  return adapterType === "claude_local" || adapterType === "codex_local" || adapterType === "acpx_local";
+}
+
 function isOverlayDirty(o: AgentConfigOverlay): boolean {
   return (
     Object.keys(o.identity).length > 0 ||
@@ -1006,7 +1010,7 @@ export function AgentConfigForm(props: AgentConfigFormProps) {
                       return result.data?.model ?? null;
                     }}
                 onRefreshModels={
-                  adapterType === "codex_local" || adapterType === "acpx_local"
+                  supportsAdapterModelRefresh(adapterType)
                     ? handleRefreshModels
                     : undefined
                 }