refactor: replace Zig terminal forwarder with Rust

[steipete]

Summary

• replace the Zig terminal forwarder with a Rust crate pinned to Rust 1.97.0
• migrate macOS, web, npm, Docker, and CI build paths to Cargo while retaining universal Darwin binaries and the Linux glibc 2.28 floor
• preserve forwarder behavior across PTY I/O, IPC control, session metadata, title filtering, signals, git metadata, and asciinema output
• make PTY backpressure interruptible, preserve non-UTF-8 Unix paths, and forward signals throughout child cleanup
• update build, testing, release, and publishing documentation; remove active Zig build/toolchain references

Validation

• Rust: fmt, Clippy with warnings denied, 51 unit tests, release build, and native Python E2E; strict shutdown suite repeated five times
• macOS: arm64/x86_64 universal build and smoke-run for both slices; app-embedded forwarder E2E
• web: check and production build; 126 test files passed, 1,624 tests passed, 103 intentionally skipped
• Linux: x64 and arm64 forwarder E2E in matching containers; maximum required GLIBC version verified at 2.28
• npm/Docker: x64 and arm64 package smoke tests; package-only Docker build, health check, Rust dispatch, and real PTY session
• docs/workflows: 57/57 documentation references, shell/JSON/JavaScript syntax checks, scoped actionlint
• final structured review clean; source-blind behavior validation found no confirmed failures

[claude]

Claude encountered an error —— View job

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I'll analyze this and get back to you.

[github-actions]

🔍 Code Quality Report

This comment is automatically updated with linting results from CI.

Node.js Biome Formatting ✅ Status: Passed

Node.js Biome Linting ✅ Status: Passed

Node.js TypeScript Type Checking ✅ Status: Passed

Node.js Build ✅ Status: Passed

Node.js Tests ✅ Status: Passed

Node.js Security Audit ✅ Status: Passed

Node.js Test Coverage ✅ Status: Passed

Client Coverage:
• Lines: 45.75%
• Functions: 40.83%
• Branches: 36.36%
• Statements: 45.87%

Server Coverage:
• Lines: 33.64%
• Functions: 40.44%
• Branches: 28.06%
• Statements: 33.22%

Mac Formatting (SwiftFormat) ✅ Status: Passed

Mac Linting (SwiftLint) ✅ Status: Passed