docs: update copilot-cli content from source docs (#63318)

Co-authored-by: github-actions[bot] <github-actions[bot]@users.noreply.github.com>
Co-authored-by: Felix Guntrip <guntrip@github.com>

Author: 3 people

content/copilot/reference/copilot-cli-reference/cli-command-reference.md

@@ -531,7 +531,7 @@ The footer shows an "N scheduled" indicator by default whenever the session has
 
 | Option                             | Purpose                                  |
 |------------------------------------|------------------------------------------|
-| `--add-dir=PATH`                   | Allow file access to a directory and load its `.github/skills` and `.github/agents` as trusted configurations (can be used multiple times). A relative path resolves against the session working directory (the `--resume`, `--worktree`, or `-C` directory), regardless of option order. |
+| `--add-dir=PATH`                   | Allow file access to a directory and load its `.github/skills` and `.github/agents` as trusted configurations (can be used multiple times). A relative path resolves against the session working directory (the `--resume`, `--worktree`, or `-C` directory), regardless of option order. The path must be an existing directory—a missing path or a regular file fails startup immediately with a flag-specific error, the same way in every mode. |
 | `--add-github-mcp-tool=TOOL`       | Add a tool to enable for the {% data variables.product.github %} MCP server, instead of the default CLI subset (can be used multiple times). Use `*` for all tools. |
 | `--add-github-mcp-toolset=TOOLSET` | Add a toolset to enable for the {% data variables.product.github %} MCP server, instead of the default CLI subset (can be used multiple times). Use `all` for all toolsets. |
 | `--additional-mcp-config=JSON`     | Add an MCP server for this session only. The server configuration can be supplied as a JSON string or a file path (prefix with `@`). A relative `@file` path resolves against the session working directory (the `--resume`, `--worktree`, or `-C` directory), regardless of option order. Augments the configuration from `~/.copilot/mcp-config.json`. Overrides any installed MCP server configuration with the same name. See [AUTOTITLE](/copilot/how-tos/copilot-cli/customize-copilot/add-mcp-servers). |

src/content-pipelines/state/copilot-cli.sha

@@ -1 +1 @@
-ceff936d1ade82fd8a7f162f19152228496b892d
+9f0895c41d269a48bde50fcd5634e72ff4815ce1