## Why
Private IP destinations always bypassed inherited upstream proxies, preventing their use for private networks reachable through an upstream VPN proxy.
## What changed
- Add `codex exec-server --proxy-private-ips-via-upstream`, also configurable with `CODEX_EXEC_SERVER_PROXY_PRIVATE_IPS_VIA_UPSTREAM=true`. The setting defaults to disabled.
- Allow permitted RFC 1918, carrier-grade NAT, and IPv6 unique-local destinations to use an applicable upstream proxy. Loopback and link-local destinations retain direct routing, and destination access policy still applies.
- Keep connections direct when no valid upstream proxy applies or `allow_upstream_proxy=false`. Errors after selecting an upstream proxy do not trigger a direct retry.
- Rename `ExecServerRuntimePaths` to `ExecServerRuntimeOptions` and carry the routing setting from executor startup into the managed network proxy.
## Testing
Add routing coverage for private address ranges, special-use addresses, and public targets with the option enabled and disabled. Verify that HTTP and CONNECT requests still enforce destination allowlists and denylists, and update the CLI help snapshot.
GitOrigin-RevId: b7c9cc7da0e0f545694a6521b74c9b36b7b92769
## Why
Sourced snapshots parse options and aliases as a group before restored options take effect. Aliases serialized with `RC_QUOTES` enabled can therefore be misinterpreted by the replay shell.
## What changed
Serialize zsh aliases for sourced snapshots with `NO_RC_QUOTES` in a subshell, preserving the captured shell options and avoiding a dependency on the optional `zsh/parameter` module.
## Testing
Extend regression coverage to execute restored aliases with `RC_QUOTES` enabled and disabled across source and eval replay. Expand macOS zsh concurrent replay tests to cover quoted aliases, preserved options, and blocked descriptor paths with and without a TTY.
GitOrigin-RevId: 48086f380c21318bece9226dfe6486c179c2a440
## Why
Large shell snapshots need a replay path that does not add their state to the child process environment.
## What changed
- Keep captured state cached in memory and give each Bash or Zsh launch an independent, read-only file descriptor to source. Unlink the file before writing shell state, create it under the sandbox-protected daemon directory, and close the carrier descriptor before restoring functions.
- Probe descriptor-path access inside the capture sandbox. Retain environment replay for `sh` and when descriptor paths are unavailable; use normal shell startup if preparing the replay file fails.
- Group options and aliases during capture so sourcing preserves their parsing behavior.
## Testing
Add coverage for concurrent replays with 480 KiB payloads, pipe and TTY execution, stdin preservation, descriptor cleanup, sandbox protection, blocked descriptor-path fallback, and alias/option parsing equivalence.
GitOrigin-RevId: 8103d5c37ce4d1885628a4efba3551549f12bea8
open-matt