Fix/coderabbit nits (#1259)

* fix: eliminate 8 as any in MCP handlers, structured output, and stream events

- Group A: Add : () => AnyObjectSchema type annotations to MCP notification
  schema constants (useIdeSelection, useIdeLogging, usePrompts, channelNotification)
- Group B: Add isStructuredOutputAttachmentMessage type guard for structured
  output attachment payloads (execAgentHook)
- Group C: Add isMessageDeltaStreamEvent type guard for message_delta
  stream event usage extraction (forkedAgent)

These as any casts also exist in the upstream CCB source — this fix provides
real type safety without changing any runtime behavior.

* feat: wire mode persona injection — Claude Soul Document distilled into system prompt

- prompts.ts: add getModePersonaSection() → injects current mode's
  systemPrompt as 'mode_persona' dynamic section (first in order,
  before operational instructions). Previously modes had systemPrompt
  fields but they were never sent to the model.
- modes/personas/claude.ts: 3KB distilled Claude persona from
  Anthropic's leaked Claude 4.5 Opus Soul Document (70KB → operational
  extract): core traits, 7 honesty principles, helpfulness/caution
  balance, collaboration stance, identity stability.
- With custom mode YAML (~/.claude/modes/claude.yaml), 7 modes total
  including the new Claude persona — fully operational at /mode claude.

Co-Authored-By: James Feng <47167674+GhostDragon124@users.noreply.github.com>

* fix: import path convention + reword persona source comment

- prompts.ts: use 'src/modes/store.js' alias instead of relative '../modes/store.js'
  to match the file's existing import convention
- claude.ts: reword JSDoc to say 'based on publicly available reference document'
  instead of 'leaked', addressing CodeRabbit review concern

src/services/mcp/channelNotification.ts

@@ -17,6 +17,7 @@
  */
 
 import type { ServerCapabilities } from '@modelcontextprotocol/sdk/types.js'
+import type { AnyObjectSchema } from '@modelcontextprotocol/sdk/server/zod-compat.js'
 import { z } from 'zod/v4'
 import { type ChannelEntry, getAllowedChannels } from '../../bootstrap/state.js'
 import { CHANNEL_TAG } from '../../constants/xml.js'
@@ -96,23 +97,24 @@ export type ChannelPermissionRequestParams = {
   }
 }
 
-export const ChannelPermissionRequestNotificationSchema = lazySchema(() =>
-  z.object({
-    method: z.literal(CHANNEL_PERMISSION_REQUEST_METHOD),
-    params: z.object({
-      request_id: z.string(),
-      tool_name: z.string(),
-      description: z.string(),
-      input_preview: z.string(),
-      channel_context: z
-        .object({
-          source_server: z.string().optional(),
-          chat_id: z.string().optional(),
-        })
-        .optional(),
+export const ChannelPermissionRequestNotificationSchema: () => AnyObjectSchema =
+  lazySchema(() =>
+    z.object({
+      method: z.literal(CHANNEL_PERMISSION_REQUEST_METHOD),
+      params: z.object({
+        request_id: z.string(),
+        tool_name: z.string(),
+        description: z.string(),
+        input_preview: z.string(),
+        channel_context: z
+          .object({
+            source_server: z.string().optional(),
+            chat_id: z.string().optional(),
+          })
+          .optional(),
+      }),
     }),
-  }),
-)
+  )
 
 /**
  * Meta keys become XML attribute NAMES — a crafted key like