feat(agent): auto-enable GLM-4.7 thinking mode

Add automatic thinking mode support for Z.AI GLM-4.x models:
- GLM-4.7: Preserved thinking (clear_thinking: false)
- GLM-4.5/4.6: Interleaved thinking (clear_thinking: true)

Uses Z.AI Cloud API format: thinking: { type: "enabled", clear_thinking: boolean }

Includes patches for pi-ai, pi-agent-core, and pi-coding-agent to pass
extraParams through the stream pipeline. User can override via config
or disable via --thinking off.

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

src/config/types.ts

@@ -982,6 +982,8 @@ export type AuthConfig = {
 
 export type AgentModelEntryConfig = {
   alias?: string;
+  /** Provider-specific API parameters (e.g., GLM-4.7 thinking mode). */
+  params?: Record<string, unknown>;
 };
 
 export type AgentModelListConfig = {

src/config/zod-schema.ts

@@ -910,6 +910,8 @@ export const ClawdbotSchema = z.object({
           z.string(),
           z.object({
             alias: z.string().optional(),
+            /** Provider-specific API parameters (e.g., GLM-4.7 thinking mode). */
+            params: z.record(z.string(), z.unknown()).optional(),
           }),
         )
         .optional(),