feat(sse): restore GPT-6 Astra effort aliases and Codex 0.153.4 pin (#13026)

Three related things that genuinely belong together: the registry and suffix splitter not knowing Astra while the live catalog serves it, the Codex client pin Astra requires, and dropping `next/font/google` so a production image build does not reach fonts.googleapis.com.

---

Validated in one consolidated worktree cut from `release/v3.8.51`, boarded with the other 19 PRs of this batch. Two in-batch conflicts, both additive and resolved by keeping each side: the `ENVIRONMENT.md` table (#13035 + #13011) and the `chatHelpers.ts` import block (#12975 on the tip + #13017).

- `typecheck:core` clean; `check:dashboard-typecheck` OK (206 pre-existing, within baseline); `check:changelog-integrity` OK; `check:docs-counts` migrations ✓
- complexity 2816 / baseline 3218 and cognitive-complexity 1271 / baseline 1437 — both under baseline
- 531 of 532 focused assertions green across the batch's 46 test files
- `check-file-size` rebaselined for the batch's real growth (annotation `_rebaseline_2026_09_11_mergebatch_v3851_houminxi`, landed on #13038), attributed per PR

The single red is **not this batch**: `tests/unit/combo/quota-weighted-strategy.test.ts` → "A/B isolation: 7 hard-empty + 2 at 0.5% + 1 at 40%, floor=1" asserts an order between two connections of identical weight and flakes on the pure tip too — 2 failures in 4 runs at `origin/release/v3.8.51` with nothing from this batch applied.

⚠️ base-red inherited: #12732 — `Docs Gates`, `Merge integrity`, `No new ESLint warnings`, `Unit Tests fast-path` and `Fast Quality Gates` reproduce on the pure tip (provider count 356 vs the 358 the modules define, SKILL.md drift, and `open-sse/utils/stream.ts` at 3115 > frozen 3098, untouched here).

Thanks @HouMinXi — the live evidence on these (X500 logs, `storage.sqlite` state, real `/v1/models` probes, the 36-minute outage write-up) is what let a 20-PR batch be reviewed as a unit.

docs/reference/PROVIDER_REFERENCE.md

@@ -1,14 +1,14 @@
 ---
 title: "Provider Reference"
 version: 3.8.51
-lastUpdated: 2026-09-03
+lastUpdated: 2026-09-05
 ---
 
 # Provider Reference
 
 > **Auto-generated** from `src/shared/constants/providers.ts` — do not edit by hand.
 > Regenerate with: `npm run gen:provider-reference`
-> **Last generated:** 2026-09-03
+> **Last generated:** 2026-09-05
 
 Total providers: **356**. See category breakdown below.