Invalid AWS Region Validation Overrides User Configuration

Bug Description
BUG REPORT: Claude Code AWS Region Issue

Problem: Claude Code refuses to accept ap-southeast-7 as Thailand region

What Happens:

• User has AWS_REGION=[REDACTED_AWS_VALUE] in config
• Claude Code says "this region doesn't exist"
• Suggests changing to ap-southeast-1 or other regions
• Ignores user corrections that it's Thailand
• Happens repeatedly, even with explicit agent / sub-agent instructions

User Experience:
User reports this issue occurs consistently across multiple interactions despite corrections

Evidence:

• User config: AWS_REGION=[REDACTED_AWS_VALUE]
• Added strong sub-agent instructions telling it NOT to correct this
• Still "corrects" the user every time

Impact:

• Can't trust Claude Code for AWS work
• Wastes time with constant corrections
• Breaks infrastructure planning
• User loses confidence in the tool

Root Cause:
Claude's training data doesn't include ap-southeast-7, so it overrides user knowledge

Fix Needed:
When user explicitly corrects AWS region info, Claude should accept it instead of "correcting" them

Severity: High - breaks AWS infrastructure work

Environment Info

• Platform: darwin
• Terminal: iTerm.app
• Version: 1.0.60
• Feedback ID: 6ad45dd3-8dd4-465f-ab80-7d17751d0084

Errors

[{"error":"Error: Command failed: security find-generic-password -a $USER -w -s \"Claude Code\"\nsecurity: SecKeychainSearchCopyNext: The specified item could not be found in the keychain.\n\n    at genericNodeError (node:internal/errors:983:15)\n    at wrappedFn (node:internal/errors:537:14)\n    at checkExecSyncError (node:child_process:892:11)\n    at execSync (node:child_process:964:15)\n    at i7 (file:///Users/greg/.claude/local/node_modules/@anthropic-ai/claude-code/cli.js:865:5196)\n    at file:///Users/greg/.claude/local/node_modules/@anthropic-ai/claude-code/cli.js:777:49014\n    at Q (file:///Users/greg/.claude/local/node_modules/@anthropic-ai/claude-code/cli.js:674:14420)\n    at kJ (file:///Users/greg/.claude/local/node_modules/@anthropic-ai/claude-code/cli.js:777:46725)\n    at XH (file:///Users/greg/.claude/local/node_modules/@anthropic-ai/claude-code/cli.js:777:45592)\n    at I9 (file:///Users/greg/.claude/local/node_modules/@anthropic-ai/claude-code/cli.js:777:51640)","timestamp":"2025-07-25T02:53:53.573Z"},{"error":"Error: Language not supported while highlighting code, falling back to markdown: \n    at BX (file:///Users/greg/.claude/local/node_modules/@anthropic-ai/claude-code/cli.js:1491:1184)\n    at file:///Users/greg/.claude/local/node_modules/@anthropic-ai/claude-code/cli.js:1491:912\n    at Array.map (<anonymous>)\n    at QX (file:///Users/greg/.claude/local/node_modules/@anthropic-ai/claude-code/cli.js:1491:903)\n    at vvB (file:///Users/greg/.claude/local/node_modules/@anthropic-ai/claude-code/cli.js:2919:40931)\n    at gM (file:///Users/greg/.claude/local/node_modules/@anthropic-ai/claude-code/cli.js:65:19859)\n    at gv (file:///Users/greg/.claude/local/node_modules/@anthropic-ai/claude-code/cli.js:67:42847)\n    at fv (file:///Users/greg/.claude/local/node_modules/@anthropic-ai/claude-code/cli.js:67:38368)\n    at RS (file:///Users/greg/.claude/local/node_modules/@anthropic-ai/claude-code/cli.js:67:38296)\n    at ZR (file:///Users/greg/.claude/local/node_modules/@anthropic-ai/claude-code/cli.js:67:38150)","timestamp":"2025-07-25T03:05:39.591Z"},{"error":"Error: Language not supported while highlighting code, falling back to markdown: \n    at BX (file:///Users/greg/.claude/local/node_modules/@anthropic-ai/claude-code/cli.js:1491:1184)\n    at file:///Users/greg/.claude/local/node_modules/@anthropic-ai/claude-code/cli.js:1491:912\n    at Array.map (<anonymous>)\n    at QX (file:///Users/greg/.claude/local/node_modules/@anthropic-ai/claude-code/cli.js:1491:903)\n    at Object.renderToolResultMessage (file:///Users/greg/.claude/local/node_modules/@anthropic-ai/claude-code/cli.js:1497:1035)\n    at __B (file:///Users/greg/.claude/local/node_modules/@anthropic-ai/claude-code/cli.js:2525:1888)\n    at gM (file:///Users/greg/.claude/local/node_modules/@anthropic-ai/claude-code/cli.js:65:19859)\n    at gv (file:///Users/greg/.claude/local/node_modules/@anthropic-ai/claude-code/cli.js:67:42847)\n    at fv (file:///Users/greg/.claude/local/node_modules/@anthropic-ai/claude-code/cli.js:67:38368)\n    at RS (file:///Users/greg/.claude/local/node_modules/@anthropic-ai/claude-code/cli.js:67:38296)","timestamp":"2025-07-25T03:09:18.874Z"},{"error":"Error: Language not supported while highlighting code, falling back to markdown: \n    at BX (file:///Users/greg/.claude/local/node_modules/@anthropic-ai/claude-code/cli.js:1491:1184)\n    at file:///Users/greg/.claude/local/node_modules/@anthropic-ai/claude-code/cli.js:1491:912\n    at Array.map (<anonymous>)\n    at QX (file:///Users/greg/.claude/local/node_modules/@anthropic-ai/claude-code/cli.js:1491:903)\n    at g_B (fil

Note: Error logs were truncated.