bump xai/grok to 4.3 and grok-fast to 4-1-fast

#1 generational bump on both. xAI shipped grok-4.3 on 2026-05-01 and
grok-4-1-fast on 2025-11-19; both are same brand tier as the existing
slugs (`grok` and `grok-fast`), so resolve + openRouterResolve update
in place with no DB migration needed. Mirrored on the openrouter
provider side (openrouter/grok now also points at x-ai/grok-4.3).

OpenRouter spells the fast variant `x-ai/grok-4.1-fast` (dot) where
models.dev uses `grok-4-1-fast` (dash) — verified both forms against
their respective live APIs before committing. See the "naming traps"
section in wiki/models-catalog.md.

Snapshot regenerated: openrouter latest-GA shifted from
poolside/laguna-xs.2:free (2026-04-28) to x-ai/grok-4.3 (2026-05-01)
as a mechanical consequence of the bump.

Verified via `pnpm -C action test:catalog` (139/139 pass against live
models.dev + OpenRouter API) and `pnpm -C action test` (458/458).

Considered and explicitly rejected during this audit (recording for
future archaeology):

- Re-adding opencode/nemotron-3-super-free: removed twice in
  71dff24c and 0f8117af with no commit-message rationale, but the
  removals are intentional per maintainer.
- Adding gpt-nano (openai + opencode + openrouter) at gpt-5.4-nano:
  the snapshot has been silently tracking opencode/gpt-5.4-nano since
  7dd80143 (2026-03-18) without a corresponding catalog addition — a
  deliberate non-add. Also would have collided with the existing
  opencode/gpt-5-nano displayName "GPT Nano".
- Adding opencode/hy3-preview-free: never been in the catalog on main
  and no positive signal beyond models.dev availability.
- Bumping opencode/gpt-5-nano (free) to opencode/gpt-5.4-nano: would
  silently turn a free alias paid ($0.20/$1.25 per M tokens) — not a
  generational bump, would require retire-and-replace if pursued.

models.ts

@@ -140,14 +140,14 @@ export const providers = {
     models: {
       grok: {
         displayName: "Grok",
-        resolve: "xai/grok-4",
-        openRouterResolve: "openrouter/x-ai/grok-4",
+        resolve: "xai/grok-4.3",
+        openRouterResolve: "openrouter/x-ai/grok-4.3",
         preferred: true,
       },
       "grok-fast": {
         displayName: "Grok Fast",
-        resolve: "xai/grok-4-fast",
-        openRouterResolve: "openrouter/x-ai/grok-4-fast",
+        resolve: "xai/grok-4-1-fast",
+        openRouterResolve: "openrouter/x-ai/grok-4.1-fast",
       },
       "grok-code-fast": {
         displayName: "Grok Code Fast",
@@ -354,8 +354,8 @@ export const providers = {
       },
       grok: {
         displayName: "Grok",
-        resolve: "openrouter/x-ai/grok-4",
-        openRouterResolve: "openrouter/x-ai/grok-4",
+        resolve: "openrouter/x-ai/grok-4.3",
+        openRouterResolve: "openrouter/x-ai/grok-4.3",
       },
       "deepseek-pro": {
         displayName: "DeepSeek Pro",

test/__snapshots__/models-catalog.main.test.ts.snap

@@ -27,8 +27,8 @@ exports[`latest model per provider snapshot > matches snapshot 1`] = `
     "releaseDate": "2026-04-24",
   },
   "openrouter": {
-    "modelId": "poolside/laguna-xs.2:free",
-    "releaseDate": "2026-04-28",
+    "modelId": "x-ai/grok-4.3",
+    "releaseDate": "2026-05-01",
   },
   "xai": {
     "modelId": "grok-4.3",