feat: rename /directory to /workspace and unify terminology

Renames the /directory command to /workspace, adds aliases for backward compatibility, and updates UI strings, settings, and prompts to use 'workspace' terminology consistently.

Linked to #20737. Per Core/UX chat on 2/18.

docs/reference/commands.md

@@ -79,8 +79,8 @@ Slash commands provide meta-level control over the CLI itself.
 - **Sub-commands:**
   - **`reload`**:
     - **Description:** Reload custom command definitions from all sources
-      (user-level `~/.gemini/commands/`, project-level
-      `<project>/.gemini/commands/`, MCP prompts, and extensions). Use this to
+      (user-level `~/.gemini/commands/`, workspace-level
+      `<workspace>/.gemini/commands/`, MCP prompts, and extensions). Use this to
       pick up new or modified `.toml` files without restarting the CLI.
     - **Usage:** `/commands reload`
 
@@ -104,7 +104,7 @@ Slash commands provide meta-level control over the CLI itself.
   - On macOS, it requires `pbcopy`, and on Windows, it requires `clip`. These
     tools are typically pre-installed on their respective systems.
 
-### `/directory` (or `/dir`)
+### `/workspace` (or `/dir`, `/directory`)
 
 - **Description:** Manage workspace directories for multi-directory support.
 - **Sub-commands:**
@@ -112,13 +112,13 @@ Slash commands provide meta-level control over the CLI itself.
     - **Description:** Add a directory to the workspace. The path can be
       absolute or relative to the current working directory. Moreover, the
       reference from home directory is supported as well.
-    - **Usage:** `/directory add <path1>,<path2>`
+    - **Usage:** `/workspace add <path1>,<path2>`
     - **Note:** Disabled in restrictive sandbox profiles. If you're using that,
       use `--include-directories` when starting the session instead.
   - **`show`**:
-    - **Description:** Display all directories added by `/directory add` and
+    - **Description:** Display all directories added by `/workspace add` and
       `--include-directories`.
-    - **Usage:** `/directory show`
+    - **Usage:** `/workspace show`
 
 ### `/docs`
 
@@ -289,7 +289,7 @@ Slash commands provide meta-level control over the CLI itself.
 
 ### `/restore`
 
-- **Description:** Restores the project files to the state they were in just
+- **Description:** Restores the workspace files to the state they were in just
   before a tool was executed. This is particularly useful for undoing file edits
   made by a tool. If run without a tool call ID, it will list available
   checkpoints to restore from.

docs/reference/configuration.md

@@ -13,7 +13,7 @@ overridden by higher numbers):
 2.  **System defaults file:** System-wide default settings that can be
     overridden by other settings files.
 3.  **User settings file:** Global settings for the current user.
-4.  **Project settings file:** Project-specific settings.
+4.  **Workspace settings file:** Workspace-specific settings.
 5.  **System settings file:** System-wide settings that override all other
     settings files.
 6.  **Environment variables:** System-wide or session-specific variables,
@@ -43,10 +43,11 @@ locations for these files:
   - **Location:** `~/.gemini/settings.json` (where `~` is your home directory).
   - **Scope:** Applies to all Gemini CLI sessions for the current user. User
     settings override system defaults.
-- **Project settings file:**
-  - **Location:** `.gemini/settings.json` within your project's root directory.
-  - **Scope:** Applies only when running Gemini CLI from that specific project.
-    Project settings override user settings and system defaults.
+- **Workspace settings file:**
+  - **Location:** `.gemini/settings.json` within your workspace's root
+    directory.
+  - **Scope:** Applies only when running Gemini CLI from that specific
+    workspace. Workspace settings override user settings and system defaults.
 - **System settings file:**
   - **Location:** `/etc/gemini-cli/settings.json` (Linux),
     `C:\ProgramData\gemini-cli\settings.json` (Windows) or
@@ -70,10 +71,11 @@ this: `"apiKey": "$MY_API_TOKEN"`. Additionally, each extension can have its own
 > CLI in a corporate environment, please see the
 > [Enterprise Configuration](../cli/enterprise.md) documentation.
 
-### The `.gemini` directory in your project
+### The `.gemini` directory in your workspace
 
-In addition to a project settings file, a project's `.gemini` directory can
-contain other project-specific files related to Gemini CLI's operation, such as:
+In addition to a workspace settings file, a workspace's `.gemini` directory can
+contain other workspace-specific files related to Gemini CLI's operation, such
+as:
 
 - [Custom sandbox profiles](#sandboxing) (e.g.,
   `.gemini/sandbox-macos-custom.sb`, `.gemini/sandbox.Dockerfile`).
@@ -1292,12 +1294,12 @@ of v0.3.0:
 ## Shell history
 
 The CLI keeps a history of shell commands you run. To avoid conflicts between
-different projects, this history is stored in a project-specific directory
+different workspaces, this history is stored in a workspace-specific directory
 within your user's home folder.
 
-- **Location:** `~/.gemini/tmp/<project_hash>/shell_history`
-  - `<project_hash>` is a unique identifier generated from your project's root
-    path.
+- **Location:** `~/.gemini/tmp/<workspace_hash>/shell_history`
+  - `<workspace_hash>` is a unique identifier generated from your workspace's
+    root path.
   - The history is stored in a file named `shell_history`.
 
 ## Environment variables and `.env` files