Config: add MiniMax direct API authentication option

Makes apiKey optional in ModelProviderConfig so MiniMax can use auth
profiles or environment variables (MINIMAX_API_KEY) instead of requiring
explicit config.

Changes:
- src/config/types.ts: apiKey changed from required to optional
- src/config/zod-schema.ts: use z.string().min(1).optional() for validation
- src/commands/configure.ts: add minimax-api auth choice in wizard
- src/commands/onboard-auth.ts: MiniMax provider omits apiKey (uses env/auth)
- patches/@mariozechner__pi-ai@0.42.1.patch: map minimax → MINIMAX_API_KEY

Auth Resolution Order (unchanged):
1. Auth profiles (highest priority)
2. Environment variables (MINIMAX_API_KEY, etc.)
3. Custom provider apiKey from models.json (lowest priority)

AGENTS.md

@@ -115,3 +115,39 @@ EOF
 ```
 
 This is a Claude Code quirk, not a clawdbot bug.
+
+---
+
+## PR & Code Review Checklist
+
+Before creating PRs or presenting code for review (especially to senior engineers):
+
+### 1. Verify Code Quality
+- [ ] Run `pnpm lint` - no errors
+- [ ] Run `pnpm build` - TypeScript compiles
+- [ ] Run related tests - all pass
+
+### 2. Review Diff Purity
+- [ ] Diff is minimal and focused on the feature
+- [ ] No unrelated changes bundled in
+- [ ] Patch files: **append** changes, don't replace entire files
+
+### 3. Self-Critique Questions
+- Is the auth resolution chain correct?
+- Are type changes safe and backwards compatible?
+- Would this pass review by John Carmack? (clarity > cleverness)
+
+### 4. Fork Workflow (when applicable)
+```bash
+# Push to fork
+git remote add fork https://github.com/USERNAME/clawdbot
+git push fork branch-name
+
+# Create PR from fork
+gh pr create --head USERNAME:branch-name --base main
+```
+
+### 5. Git Diff Interpretation
+- `-` lines = content being **removed**
+- `+` lines = content being **added**
+- Verify you understand what the diff actually shows

patches/@mariozechner__pi-ai@0.42.1.patch

@@ -55,3 +55,16 @@ index 20fb0a22aaa28f7ff7c2f44a8b628fa1d9d7d936..0bf46bfb4a6fac5a0304652e42566b2c
                          const reasoningItem = JSON.parse(block.thinkingSignature);
                          output.push(reasoningItem);
                      }
+
+diff --git a/dist/stream.js b/dist/stream.js
+index 0000000..2222222 100644
+--- a/dist/stream.js
++++ b/dist/stream.js
+@@ -43,6 +43,7 @@ export function getEnvApiKey(provider) {
+         xai: "XAI_API_KEY",
+         openrouter: "OPENROUTER_API_KEY",
+         zai: "ZAI_API_KEY",
++        minimax: "MINIMAX_API_KEY",
+         mistral: "MISTRAL_API_KEY",
+     };
+     const envVar = envMap[provider];

src/commands/configure.ts

@@ -70,6 +70,7 @@ import { healthCommand } from "./health.js";
 import { formatHealthCheckFailure } from "./health-format.js";
 import {
   applyAuthProfileConfig,
+  applyMinimaxApiConfig,
   applyMinimaxConfig,
   applyMinimaxHostedConfig,
   applyOpencodeZenConfig,
@@ -369,6 +370,7 @@ async function promptAuthConfig(
     | "gemini-api-key"
     | "apiKey"
     | "minimax-cloud"
+    | "minimax-api"
     | "minimax"
     | "opencode-zen"
     | "skip";
@@ -788,6 +790,21 @@ async function promptAuthConfig(
     next = applyMinimaxHostedConfig(next);
   } else if (authChoice === "minimax") {
     next = applyMinimaxConfig(next);
+  } else if (authChoice === "minimax-api") {
+    const key = guardCancel(
+      await text({
+        message: "Enter MiniMax API key",
+        validate: (value) => (value?.trim() ? undefined : "Required"),
+      }),
+      runtime,
+    );
+    await setMinimaxApiKey(String(key).trim());
+    next = applyAuthProfileConfig(next, {
+      profileId: "minimax:default",
+      provider: "minimax",
+      mode: "api_key",
+    });
+    next = applyMinimaxApiConfig(next);
   } else if (authChoice === "opencode-zen") {
     note(
       [

src/commands/onboard-auth.ts

@@ -336,7 +336,7 @@ export function applyMinimaxApiProviderConfig(
   const providers = { ...cfg.models?.providers };
   providers.minimax = {
     baseUrl: MINIMAX_API_BASE_URL,
-    apiKey: "", // Resolved via MINIMAX_API_KEY env var or auth profile
+    // apiKey omitted: resolved via MINIMAX_API_KEY env var or auth profile by default.
     api: "anthropic-messages",
     models: [buildMinimaxApiModelDefinition(modelId)],
   };

src/config/types.ts

@@ -1201,7 +1201,7 @@ export type ModelDefinitionConfig = {
 
 export type ModelProviderConfig = {
   baseUrl: string;
-  apiKey: string;
+  apiKey?: string;
   api?: ModelApi;
   headers?: Record<string, string>;
   authHeader?: boolean;

src/config/zod-schema.ts

@@ -40,7 +40,7 @@ const ModelDefinitionSchema = z.object({
 
 const ModelProviderSchema = z.object({
   baseUrl: z.string().min(1),
-  apiKey: z.string().min(1),
+  apiKey: z.string().min(1).optional(),
   api: ModelApiSchema.optional(),
   headers: z.record(z.string(), z.string()).optional(),
   authHeader: z.boolean().optional(),