feat(providers): add MiniMax (global + China) via Anthropic Messages

Providers 21-22 (24th & 25th registry variants), sourced from Pi
(earendil-works/pi). Pi drives MiniMax through its Anthropic-COMPATIBLE
surface (baseUrl .../anthropic), so Kigi reuses the existing Anthropic
Messages machinery (wire_api=Messages, listing=Anthropic, key_header=XApiKey
x-api-key+anthropic-version) rather than the OpenAI path. Global:
api.minimax.io/anthropic, MINIMAX_API_KEY, models.dev minimax. China:
api.minimaxi.com/anthropic, MINIMAX_CN_API_KEY, models.dev minimax-cn.

The base carries the /v1 suffix (.../anthropic/v1) since Kigi appends bare
paths → listing .../anthropic/v1/models?limit=1000, inference
.../anthropic/v1/messages (matches the live-probed x-api-key-gated endpoint).
restrict_to_enriched=FALSE: the 7 MiniMax-M* models are clean (no pollution)
and restrict would drop launch-day models not yet in models.dev.

Also HARDENS parse_anthropic_listing to tolerate a bare array in addition to
the {data:[...]} envelope (mirrors parse_openai_listing's sniff that Together
taught us) — so MiniMax's Anthropic-compatible /models can't silently empty
the catalog if it serves a bare array. A bare object without data still errors.

Review found no defects (5 areas CONFIRMED incl. the /v1 non-doubling, the
additive parser change, restrict=false rationale). Residual (logged): the live
200 body / anthropic-version acceptance is unverifiable without a key; the
bare-array tolerance + restrict=false hedge most shapes.

Tests: e2e mocks the x-api-key-gated Anthropic listing (proves the auth header
+ enrichment + keying under minimax/); both validation tests reject 401 with
the per-variant console host; new parser test covers envelope + bare array +
bare-object-errors. Registry at 25; picker 26 rows.

crates/codegen/kigi-tui/src/app/app_view.rs

@@ -6894,7 +6894,7 @@ pub(crate) mod tests {
     #[test]
     fn pending_menu_items_lists_interactive_methods_plus_quit() {
         let items = pending_menu_items(&fresh_user_auth_methods(), None);
-        assert_eq!(items.len(), 24, "23 login rows + Quit, got {items:?}");
+        assert_eq!(items.len(), 26, "25 login rows + Quit, got {items:?}");
         assert!(
             matches!(&items[0], PendingMenuItem::Login { label } if label == "Kimi Code (OAuth)"),
             "row 0 must be the OAuth login, got {:?}",
@@ -7055,7 +7055,21 @@ pub(crate) mod tests {
                 label: "Xiaomi Token Plan China (API key)".into(),
             }
         );
-        assert_eq!(items[23], PendingMenuItem::Quit);
+        assert_eq!(
+            items[23],
+            PendingMenuItem::ApiKey {
+                target: PlatformLogin(kigi_shell::models::PlatformId::Minimax),
+                label: "MiniMax (API key)".into(),
+            }
+        );
+        assert_eq!(
+            items[24],
+            PendingMenuItem::ApiKey {
+                target: PlatformLogin(kigi_shell::models::PlatformId::MinimaxCn),
+                label: "MiniMax China (API key)".into(),
+            }
+        );
+        assert_eq!(items[25], PendingMenuItem::Quit);
         // The non-interactive methods must never appear as rows.
         let byok = kigi_shell::agent::auth_method::build_auth_methods(
             kigi_shell::agent::auth_method::AuthMethodsBuildInputs {
@@ -7066,7 +7080,7 @@ pub(crate) mod tests {
         );
         assert_eq!(
             pending_menu_items(&byok.methods, None).len(),
-            24,
+            26,
             "xai.api_key / cached_token must not add rows"
         );
     }