[Bug] /setup-bedrock propagates shell env to all active sessions, causing mid-session model switches and session loss

Bug: /setup-bedrock wizard corrupts all active Claude Code sessions via shell env propagation
Version: 2.1.110
Summary: Running /setup-bedrock in one Claude Code session caused all other active CC sessions to switch to Bedrock mid-session, triggering model availability errors and abnormal exits that wiped session history across all projects.
Steps to reproduce:

Have multiple Claude Code sessions open across different projects, all using Claude Max subscription
In one session, run /setup-bedrock to configure a single project for Bedrock
All other open CC sessions immediately switch to Bedrock and begin throwing model availability errors
Sessions exit abnormally; claude --continue reports no session found for sessions that were just active

Expected behavior: /setup-bedrock should only affect the current session. Other running sessions should be unaffected.
Actual behavior: The wizard sets CLAUDE_CODE_USE_BEDROCK=1 in the live shell environment, which propagates to all child/sibling shell processes running other CC instances, switching them all to Bedrock mid-session. Abnormal exits caused by model errors then prevent session recovery.
Impact: Complete loss of session history across all open projects. Sessions cannot be resumed with --continue.
Workaround: Run /setup-bedrock only in a fresh terminal with no other CC sessions open.

Environment Info

• Platform: darwin
• Terminal: WarpTerminal
• Version: 2.1.110
• Feedback ID: ad4af11e-2792-41ef-969d-1df03b0a1d29

Errors

[{"error":"Error: NON-FATAL: Lock acquisition failed for /Users/abradley/.local/share/claude/versions/2.1.110 (expected in multi-process scenarios)\n    at kU_ (/$bunfs/root/src/entrypoints/cli.js:2751:2153)\n    at Mt6 (/$bunfs/root/src/entrypoints/cli.js:2751:1233)\n    at processTicksAndRejections (native:7:39)","timestamp":"2026-04-16T01:00:17.523Z"},{"error":"Error: Duplicate hooks file detected: ./hooks/hooks.json resolves to already-loaded file /Users/abradley/.claude/plugins/cache/everything-claude-code/everything-claude-code/1.0.0/hooks/hooks.json. The standard hooks/hooks.json is loaded automatically, so manifest.hooks should only reference additional hook files.\n    at Mz9 (/$bunfs/root/src/entrypoints/cli.js:1035:6544)\n    at async Pz9 (/$bunfs/root/src/entrypoints/cli.js:1035:12757)\n    at processTicksAndRejections (native:7:39)","timestamp":"2026-04-16T01:00:17.542Z"},{"error":"Error: Duplicate hooks file detected: ./hooks/hooks.json resolves to already-loaded file /Users/abradley/.claude/plugins/cache/everything-claude-code/everything-claude-code/1.0.0/hooks/hooks.json. The standard hooks/hooks.json is loaded automatically, so manifest.hooks should only reference additional hook files.\n    at Mz9 (/$bunfs/root/src/entrypoints/cli.js:1035:6544)\n    at async Pz9 (/$bunfs/root/src/entrypoints/cli.js:1035:12757)\n    at processTicksAndRejections (native:7:39)","timestamp":"2026-04-16T01:00:23.739Z"}]