Extend account groups with manager and launch workflows

[mouaadsk]

Summary

• Extend managed account groups with transfer workflows, project launch memory, grouped dashboard output, and one background manager for per-group auto-switching.
• Add local usage-limit message detection from each enabled group’s session logs.
• Add launch/resume helpers so users do not need to manually prefix commands with CODEX_HOME.

Depends on

• Depends on Add account groups with isolated CODEX_HOME support #75 and should be reviewed after that PR.
• This branch is stacked on pr/account-groups-core. Because the upstream repository does not have that branch, this draft targets main for now. After Add account groups with isolated CODEX_HOME support #75 merges, this PR should show only the follow-up changes; if upstream edits Add account groups with isolated CODEX_HOME support #75 during review, this branch can be rebased.

What changed

• Adds grouped list dashboard with group sections and a GROUP column.
• Adds group copy and move, including interactive selection.
• Adds group archive/delete lifecycle.
• Adds per-group auto, config api, and status commands.
• Adds one manager daemon/service for all enabled groups across Linux, macOS, and Windows.
• Adds codex-auth launch, group <name> launch resume, and project-to-group memory.
• Updates schema/docs/tests for the extended behavior.

Testing

• zig build run -- list
• zig build run -- group --help
• zig build test
• zig test src/main.zig -lc passes 428 tests
• zig build -Dtarget=x86_64-linux-gnu
• zig build -Dtarget=x86_64-windows-gnu