chore: switch Claude review bot to custom proxy endpoint and opus-4.6-1m model

Update model from claude-opus-4-6 to claude-opus-4.6-1m for both
auto-resolve and main review steps. API endpoint and key updated
via GitHub Secrets (ANTHROPIC_PROXY_URL, ANTHROPIC_PROXY_KEY).

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Author: ZhaoChaoqun

.github/workflows/claude-review.yml

@@ -113,7 +113,7 @@ jobs:
           anthropic_api_key: ${{ secrets.ANTHROPIC_PROXY_KEY }}
           use_sticky_comment: false
           claude_args: >-
-            --model claude-opus-4-6
+            --model claude-opus-4.6-1m
             --max-turns 20
             --allowedTools Bash(gh api repos:*),Bash(gh api graphql:*),Bash(git diff:*),Bash(git log:*),Read
           prompt: |
@@ -229,7 +229,7 @@ jobs:
           use_sticky_comment: true
           show_full_output: true
           claude_args: >-
-            --model claude-opus-4-6
+            --model claude-opus-4.6-1m
             --max-turns 50
             --allowedTools Task,Read,Glob,Grep,Bash(git diff:*),Bash(git show:*),Bash(gh pr view:*),mcp__github_comment__create_or_update_comment,mcp__github_comment__create_comment,mcp__github_comment__update_claude_comment,mcp__github_inline_comment__create_inline_comment,mcp__github_inline_comment__create_review
           prompt: |