[Bug]: Claude provider ignores ~/.claude/settings.json env, so proxy-backed Claude fails #1267

Before submitting

• I searched existing issues and did not find a duplicate.
• I included enough detail to reproduce or investigate the problem.

Area

apps/server

Steps to reproduce

1. Configure Claude Code to use a proxy-backed setup via environment variables in ~/.claude/settings.json under the top-level env field.
2. Verify claude code works normally from the same machine without needing an interactive Claude login flow.
3. Start T3 Code and select the Claude provider.
4. Send a prompt.

Expected behavior

T3 Code should start Claude with the same effective environment Claude Code uses, including env vars from ~/.claude/settings.json, so proxy-backed Claude sessions work normally.

Actual behavior

T3 Code launched Claude with only the app/server process.env and did not load env vars from ~/.claude/settings.json. In setups where Claude depends on proxy-related env from that file, Claude failed at runtime and reported a login error such as “Not logged in” / “Please run /login”, even though Claude Code itself worked on the same machine.

Impact

Blocks work completely

Version or commit

latest

Environment

macOS, T3 Code desktop/server, Claude provider, proxy-backed Claude Code setup via ~/.claude/settings.json

Logs or stack traces

Screenshots, recordings, or supporting files

No response

Workaround

Running claude code directly worked because it picked up env from ~/.claude/settings.json. T3 Code only worked after adding support to read that file and merge its env values over process.env.