feat(ui): implement refreshed UX for Composer layout

- Promotes refreshed multi-row status area and footer as the default experience.
- Stabilizes Composer row heights to prevent layout 'jitter' during typing and model turns.
- Unifies active hook status and model loading indicators into a single, stable Row 1.
- Refactors settings to use backward-compatible 'Hide' booleans (ui.hideStatusTips, ui.hideStatusWit).
- Removes vestigial context usage bleed-through logic in minimal mode to align with global UX direction.
- Relocates toast notifications to the top status row for improved visibility.
- Updates all CLI UI snapshots and architectural tests to reflect the stabilized layout.

docs/reference/commands.md

@@ -14,31 +14,6 @@ Slash commands provide meta-level control over the CLI itself.
 
 - **Description:** Show version info. Share this information when filing issues.
 
-### `/agents`
-
-- **Description:** Manage local and remote subagents.
-- **Note:** This command is experimental and requires
-  `experimental.enableAgents: true` in your `settings.json`.
-- **Sub-commands:**
-  - **`list`**:
-    - **Description:** Lists all discovered agents, including built-in, local,
-      and remote agents.
-    - **Usage:** `/agents list`
-  - **`reload`** (alias: `refresh`):
-    - **Description:** Rescans agent directories (`~/.gemini/agents` and
-      `.gemini/agents`) and reloads the registry.
-    - **Usage:** `/agents reload`
-  - **`enable`**:
-    - **Description:** Enables a specific subagent.
-    - **Usage:** `/agents enable <agent-name>`
-  - **`disable`**:
-    - **Description:** Disables a specific subagent.
-    - **Usage:** `/agents disable <agent-name>`
-  - **`config`**:
-    - **Description:** Opens a configuration dialog for the specified agent to
-      adjust its model, temperature, or execution limits.
-    - **Usage:** `/agents config <agent-name>`
-
 ### `/auth`
 
 - **Description:** Open a dialog that lets you change the authentication method.