feat(athena): update council member candidates with upgraded models

- Claude sonnet → opus 4.6, GPT 5.2 → 5.3 codex, Gemini flash → pro preview
- Replace copilot/opencode-zen candidates with kimi-for-coding/k2p5
- Update test cases and regenerate model-fallback snapshots
- All 2688 tests pass, typecheck clean

src/cli/council-members-generator.ts

@@ -12,29 +12,24 @@ const COUNCIL_CANDIDATES: Array<{
 }> = [
   {
     provider: (a) => a.native.claude,
-    model: "anthropic/claude-sonnet-4-5",
-    name: "Claude",
+    model: "anthropic/claude-opus-4-6",
+    name: "Claude Opus 4.6",
   },
   {
     provider: (a) => a.native.openai,
-    model: "openai/gpt-5.2",
-    name: "GPT",
+    model: "openai/gpt-5.3-codex",
+    name: "GPT 5.3 Codex",
   },
   {
     provider: (a) => a.native.gemini,
-    model: "google/gemini-3-flash",
-    name: "Gemini",
+    model: "google/gemini-3-pro-preview",
+    name: "Gemini Pro 3",
   },
   {
-    provider: (a) => a.copilot,
-    model: "github-copilot/gpt-5.2",
-    name: "Copilot GPT",
-  },
-  {
-    provider: (a) => a.opencodeZen,
-    model: "opencode/claude-sonnet-4-5",
-    name: "OpenCode Claude",
-  },
+    provider: (a) => a.kimiForCoding,
+    model: "kimi-for-coding/k2p5",
+    name: "Kimi 2.5",
+  }
 ]
 
 export function generateCouncilMembers(avail: ProviderAvailability): CouncilMember[] {