fix(providers): complete Hack Club AI removal from shared catalog (#11176)

PR #11118/#11123 removed hackclub from the open-sse REGISTRY but the
canonical shared catalog kept the entry, so the dashboard, alias resolver,
icon registry, onboarding i18n strings and the generated provider reference
kept advertising a provider the router no longer serves.

Removed:
- APIKEY_PROVIDERS hackclub entry (id + "hc" alias) in apikey/gateways.ts
- hackclub from ProviderIcon KNOWN_SVGS + public/providers/hackclub.svg asset
- providers.onboardingProviderDescriptions.hackclub from all 43 locales
- stale comments referencing hackclub as a living provider (web-cookie.ts,
  registry/huggingchat, registry/g4f-groq, registry/freetheai, test prose)

Count cascade 351 -> 350 (measured per-file; the live catalog union across
all 11 provider collections goes 351 -> 350):
- README.md, AGENTS.md, llm.txt + 42 i18n llm.txt mirrors (byte-identical
  bodies, docs-sync gate green), package.json description
- docs/reference/PROVIDER_REFERENCE.md regenerated (gen-provider-reference)
- canonical numbers in readme-hero/promise-pillars/comparison-table/
  cli-terminal SVGs (docs-counts-sync STRICT gate green)

Kept intentionally (historical records, not catalog):
- CHANGELOG.md + docs/i18n/*/CHANGELOG.md entries from when the provider
  was added (#2339, #2611) — release history
- src/lib/db/migrations/162_remove_hackclub_provider.sql — the removal
  migration itself
- tests/unit/remove-hackclub-11118.test.ts — the REGISTRY removal guard

Validation: new tests/unit/hackclub-removed.test.ts (5 asserts: catalog
absence, hc alias free, structural grep over provider sources, icon/asset
gone, i18n key gone) fails before / passes after; provider sibling tests
46 pass; provider-catalog consumer batch 268 pass; typecheck:core clean;
eslint clean on touched files; check:provider-consistency OK (350
canonical); check:docs-counts-sync + check:docs-sync green.

Closes #11176

docs/reference/PROVIDER_REFERENCE.md

@@ -10,7 +10,7 @@ lastUpdated: 2026-08-23
 > Regenerate with: `npm run gen:provider-reference`
 > **Last generated:** 2026-08-23
 
-Total providers: **351**. See category breakdown below.
+Total providers: **350**. See category breakdown below.
 
 ## Categories
 
@@ -122,7 +122,7 @@ Use the dashboard at `/dashboard/providers` to enable, configure, and test each
 | `zai-web` | `zw` | Z.ai Web | Web cookie | [link](https://chat.z.ai) | Copy the "token" value from chat.z.ai → DevTools → Application → Local Storage. Do not copy cookies; OmniRoute handles the per-request CAPTCHA through its browser transport. | — |
 | `zenmux-free` | `zmf` | ZenMux Free (Web) | Web cookie | [link](https://zenmux.ai) | Login at zenmux.ai, then export all cookies using EditThisCookie or Cookie-Editor and paste the full Cookie header string here. Refresh every ~30 days. | — |
 
-## API Key Providers (paid / paid-with-free-credits) (232)
+## API Key Providers (paid / paid-with-free-credits) (231)
 
 | ID | Alias | Name | Tags | Website | Notes |
 |----|-------|------|------|---------|-------|
@@ -215,7 +215,6 @@ Use the dashboard at `/dashboard/providers` to enable, configure, and test each
 | `glm-cn` | `glmcn` | GLM Coding (China) | API key | [link](https://open.bigmodel.cn) | — |
 | `glmt` | `glmt` | GLM Thinking | API key | [link](https://open.bigmodel.cn) | — |
 | `groq` | `groq` | Groq | API key | [link](https://groq.com) | Free tier: 30 RPM / 14.4K RPD — no credit card |
-| `hackclub` | `hc` | Hackclub AI | API key | [link](https://ai.hackclub.com) | Sign in with your Hack Club account at ai.hackclub.com. |
 | `haiper` | `hp` | Haiper | API key, video | [link](https://haiper.ai) | Get API key at haiper.ai/haiper-api |
 | `hcnsec` | `hcnsec` | Huancheng Public API | API key | [link](https://api.hcnsec.cn) | Get API key at api.hcnsec.cn |
 | `helixmind` | `helixmind` | HelixMind | API key, aggregator | [link](https://helixmind.online) | Previously circulated 3 RPM/50 RPD and no-card claims were not confirmed during the 2026-08-02 audit; current quota and billing require account verification. |