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/utils/approval-presets/src/lib.rs

@@ -0,0 +1,46 @@
+use codex_core::protocol::AskForApproval;
+use codex_core::protocol::SandboxPolicy;
+
+/// A simple preset pairing an approval policy with a sandbox policy.
+#[derive(Debug, Clone)]
+pub struct ApprovalPreset {
+    /// Stable identifier for the preset.
+    pub id: &'static str,
+    /// Display label shown in UIs.
+    pub label: &'static str,
+    /// Short human description shown next to the label in UIs.
+    pub description: &'static str,
+    /// Approval policy to apply.
+    pub approval: AskForApproval,
+    /// Sandbox policy to apply.
+    pub sandbox: SandboxPolicy,
+}
+
+/// Built-in list of approval presets that pair approval and sandbox policy.
+///
+/// Keep this UI-agnostic so it can be reused by both TUI and MCP server.
+pub fn builtin_approval_presets() -> Vec<ApprovalPreset> {
+    vec![
+        ApprovalPreset {
+            id: "read-only",
+            label: "Read Only",
+            description: "Codex can read files in the current workspace. Approval is required to edit files or access the internet.",
+            approval: AskForApproval::OnRequest,
+            sandbox: SandboxPolicy::ReadOnly,
+        },
+        ApprovalPreset {
+            id: "auto",
+            label: "Default",
+            description: "Codex can read and edit files in the current workspace, and run commands. Approval is required to access the internet or edit other files. (Identical to Agent mode)",
+            approval: AskForApproval::OnRequest,
+            sandbox: SandboxPolicy::new_workspace_write_policy(),
+        },
+        ApprovalPreset {
+            id: "full-access",
+            label: "Full Access",
+            description: "Codex can edit files outside this workspace and access the internet without asking for approval. Exercise caution when using.",
+            approval: AskForApproval::Never,
+            sandbox: SandboxPolicy::DangerFullAccess,
+        },
+    ]
+}