fix(free-tiers): retire 4 re-verified-dead free tiers, flag iflytek/sparkdesk ToS, clarify monsterapi one-time (#4152)

Case-by-case follow-up on the 2026-06-17 refresh deferred items. Each dead tier was
re-verified against its official source on 2026-06-18 before flipping (qwen-web lesson):

- aimlapi -> hasFree:false. docs.aimlapi.com/faq/free-tier states "The Free Tier is
  currently paused"; now pay-as-you-go (min $20 top-up).
- gitlawb + gitlawb-gmi -> hasFree:false. Free MiMo revoked 2026-05-24 (GitHub
  Gitlawb/openclaude#1345 "OPENGATEWAY REVOKED THE ONLY 1 FREE MODEL"); Nemotron promo
  ended 2026-06; Opengateway is now a pay-as-you-go credit gateway. Removed 40 stale
  gitlawb-gmi catalog records.
- yi -> hasFree:false. Yi-Light retired; platform.01.ai is pay-as-you-go (Yi-Lightning
  paid); open weights are download-only. Removed 1 stale catalog record.
- iflytek / sparkdesk -> kept hasFree:true with a ToS-caution freeNote: Spark Lite is
  free but the ToS prohibits programmatic extraction / relay to third parties (iflytek
  also requires Chinese real-name auth).
- monsterapi -> freeNote tightened to "one-time signup trial" (recurring plan = 0
  credits/mo); the budget catalog already classified it one-time-initial.

The dead providers stay registered (paid use still works); only the free-tier
advertisement is removed. FREE_TIERS.md "Removed" note + budget table reconciled.

Tests: gitlawb-provider guard updated (hasFree now false for both gitlawb variants);
discontinued-providers-2026 extended to cover the 4 new flips + an iflytek ToS-caution
assertion. Re-verified live 2026-06-18 (Hard Rule #18).

src/shared/constants/providers.ts

@@ -1730,8 +1730,8 @@ export const APIKEY_PROVIDERS = {
     color: "#10B981",
     textIcon: "GLB",
     website: "https://opengateway.gitlawb.com",
-    hasFree: true,
-    freeNote: "Free tier available — no credit card required",
+    hasFree: false,
+    freeNote: "Free MiMo (xiaomi/mimo-v2.5) revoked 2026-05 — Opengateway is now a pay-as-you-go credit gateway; no recurring free model.",
     apiHint: "Get your API key from Gitlawb Opengateway dashboard.",
   },
   "gitlawb-gmi": {
@@ -1742,8 +1742,8 @@ export const APIKEY_PROVIDERS = {
     color: "#10B981",
     textIcon: "GMI",
     website: "https://opengateway.gitlawb.com",
-    hasFree: true,
-    freeNote: "Free tier available — no credit card required",
+    hasFree: false,
+    freeNote: "Free Nemotron promo ended 2026-06 — the GMI Cloud route is now pay-as-you-go credit only.",
     apiHint: "Get your API key from Gitlawb Opengateway dashboard.",
   },
   "inference-net": {
@@ -1796,9 +1796,9 @@ export const APIKEY_PROVIDERS = {
     color: "#6366F1",
     textIcon: "AI",
     website: "https://aimlapi.com",
-    hasFree: true,
+    hasFree: false,
     freeNote:
-      "$0.025/day free credits — 200+ models (GPT-4o, Claude, Gemini, Llama) via single endpoint",
+      "Free tier paused (2026) — AI/ML API is now pay-as-you-go only (min $20 top-up); no recurring free credits.",
     passthroughModels: true,
   },
   novita: {
@@ -2058,7 +2058,7 @@ export const APIKEY_PROVIDERS = {
     textIcon: "IF",
     website: "https://xinghuo.xfyun.cn",
     hasFree: true,
-    freeNote: "Free Spark Lite models. China's voice AI leader.",
+    freeNote: "Spark Lite is free (2 QPS rate-limited), but iFlytek ToS §2.4(3) prohibits programmatic extraction and requires Chinese real-name auth — use with caution.",
     passthroughModels: true,
     authHint: "Get API key at console.xfyun.cn",
   },
@@ -2083,8 +2083,8 @@ export const APIKEY_PROVIDERS = {
     color: "#10B981",
     textIcon: "YI",
     website: "https://01.ai",
-    hasFree: true,
-    freeNote: "Free Yi-Light models. Kai-Fu Lee's company.",
+    hasFree: false,
+    freeNote: "No free API tier (2026) — Yi-Light retired; platform.01.ai is pay-as-you-go (Yi-Lightning paid). Open weights are download-only.",
     passthroughModels: true,
     authHint: "Get API key at platform.lingyiwanwu.com",
   },
@@ -2162,7 +2162,7 @@ export const APIKEY_PROVIDERS = {
     textIcon: "SD",
     website: "https://xinghuo.xfyun.cn",
     hasFree: true,
-    freeNote: "Free iFlytek Spark models (alias for iflytek).",
+    freeNote: "Spark Lite free (alias for iflytek), but ToS restricts to personal/non-commercial use and prohibits relaying access to third parties — use with caution.",
     passthroughModels: true,
     authHint: "Get API key at console.xfyun.cn",
   },
@@ -2267,7 +2267,7 @@ export const APIKEY_PROVIDERS = {
     textIcon: "MA",
     website: "https://monsterapi.ai",
     hasFree: true,
-    freeNote: "Free credits for decentralized GPU inference. No credit card required.",
+    freeNote: "One-time signup trial credits for decentralized GPU inference (no recurring free plan). No credit card required.",
     passthroughModels: true,
     authHint: "Get API key at monsterapi.ai",
   },