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/lib.rs

@@ -14,8 +14,6 @@ pub use cli::Cli;
 pub use cli::Command;
 pub use cli::ReviewArgs;
 use codex_cloud_requirements::cloud_requirements_loader;
-use codex_common::oss::ensure_oss_provider_ready;
-use codex_common::oss::get_default_model_for_oss_provider;
 use codex_core::AuthManager;
 use codex_core::LMSTUDIO_OSS_PROVIDER_ID;
 use codex_core::NewThread;
@@ -43,6 +41,8 @@ use codex_protocol::approvals::ElicitationAction;
 use codex_protocol::config_types::SandboxMode;
 use codex_protocol::user_input::UserInput;
 use codex_utils_absolute_path::AbsolutePathBuf;
+use codex_utils_oss::ensure_oss_provider_ready;
+use codex_utils_oss::get_default_model_for_oss_provider;
 use event_processor_with_human_output::EventProcessorWithHumanOutput;
 use event_processor_with_jsonl_output::EventProcessorWithJsonOutput;
 use serde_json::Value;