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/tui/src/bottom_pane/slash_commands.rs

@@ -3,7 +3,7 @@
 //! The same sandbox- and feature-gating rules are used by both the composer
 //! and the command popup. Centralizing them here keeps those call sites small
 //! and ensures they stay in sync.
-use codex_common::fuzzy_match::fuzzy_match;
+use codex_utils_fuzzy_match::fuzzy_match;
 
 use crate::slash_command::SlashCommand;
 use crate::slash_command::built_in_slash_commands;