feat: split codex-common into smaller utils crates (#11422)

We are removing feature-gated shared crates from the `codex-rs`
workspace. `codex-common` grouped several unrelated utilities behind
`[features]`, which made dependency boundaries harder to reason about
and worked against the ongoing effort to eliminate feature flags from
workspace crates.

Splitting these utilities into dedicated crates under `utils/` aligns
this area with existing workspace structure and keeps each dependency
explicit at the crate boundary.

## What changed

- Removed `codex-rs/common` (`codex-common`) from workspace members and
workspace dependencies.
- Added six new utility crates under `codex-rs/utils/`:
  - `codex-utils-cli`
  - `codex-utils-elapsed`
  - `codex-utils-sandbox-summary`
  - `codex-utils-approval-presets`
  - `codex-utils-oss`
  - `codex-utils-fuzzy-match`
- Migrated the corresponding modules out of `codex-common` into these
crates (with tests), and added matching `BUILD.bazel` targets.
- Updated direct consumers to use the new crates instead of
`codex-common`:
  - `codex-rs/cli`
  - `codex-rs/tui`
  - `codex-rs/exec`
  - `codex-rs/app-server`
  - `codex-rs/mcp-server`
  - `codex-rs/chatgpt`
  - `codex-rs/cloud-tasks`
- Updated workspace lockfile entries to reflect the new dependency graph
and removal of `codex-common`.

codex-rs/exec/src/main.rs

@@ -11,9 +11,9 @@
 //! of the `codex-exec` binary.
 use clap::Parser;
 use codex_arg0::arg0_dispatch_or_else;
-use codex_common::CliConfigOverrides;
 use codex_exec::Cli;
 use codex_exec::run_main;
+use codex_utils_cli::CliConfigOverrides;
 
 #[derive(Parser, Debug)]
 struct TopCli {