Copilot CLI 1.0.109 adds Claude Fable 5.2 to the model picker and CIDR rules for the sandbox

GitHub's Copilot CLI 1.0.109 adds:

• Models: Claude Fable 5.2 appears in the model picker under New models. An error now shows when a selected or saved model is unavailable, instead of silently switching to another one.
• Sandbox: sandbox host allow and deny rules in settings accept IPv4 and IPv6 CIDR ranges. On Linux, denied paths now also block access to developer-tool configuration files inside them. Sandboxed git gets a masked credential that the sandbox proxy swaps for the real one only at the matching HTTPS origin.
• Permissions: URL permission prompts let you approve every subdomain for the current session; MCP allow rules now match a tool under the name its server advertises, as deny rules already did; /share and /export ask before following symlinks; file move prompts show both source and destination; read-only shell scripts prompt less often, while scripts that change git refs or read files through hidden paths are always reviewed.
• Commands: text typed after /init now reaches the model as extra guidance for the generated instructions file; running /research again on the same topic saves a new report instead of trying to overwrite the earlier one; Backspace at the start of shell input leaves shell mode and keeps the typed text; /rubber-duck is offered on the default model from the start of a session.
• MCP: tool results returned as a base64 text blob now reach the model instead of arriving empty; a mistyped server in mcp-config.json is reported at startup and in mcp list; copilot mcp list and get honor --additional-mcp-config and --plugin-dir.
• Indexing: indexed search now deletes leftover per-repository indexes for repositories that no longer exist, including those written by 1.0.108, which the release says could grow to tens of gigabytes.

The release also carries many fixes to terminal display, sessions, Windows memory use, and help text and setting descriptions.