Add MiMo Code integration installers

[luca-ctx]

Summary

• add MiMo Code as an explicit MCP integration target using native MiMo config paths
• add MiMo Code slash-command and skill installer targets
• cover MiMo config/command/skill paths with fake-harness and installer tests
• update MCP, slash-command, skill, and CLI reference docs
• clean public package audit blockers by removing a tracked manager execution-plan artifact and tightening stale audit/default-path issues

Verification

• TMPDIR=$PWD/target/tmp cargo check -q -p ctx --tests
• TMPDIR=$PWD/target/tmp cargo test -q -p ctx
• TMPDIR=$PWD/target/tmp cargo test -q -p ctx --test mcp_integration_e2e
• TMPDIR=$PWD/target/tmp cargo test -q -p ctx --test slash_command_e2e
• TMPDIR=$PWD/target/tmp cargo test -q -p ctx --test skill
• TMPDIR=$PWD/target/tmp cargo test -q -p ctx --test integrations_mcp
• TMPDIR=$PWD/target/tmp bash scripts/check.sh -- test //:buildkite_pipeline_check //:cargo_check //:cargo_fmt_check //:docs_check //:installer_path_smoke //:loc_check //:package_audit_fast //:source_diff_check --config=ci
• Buildkite buildkite/ctx-public-ci build fix(cli): avoid initializing the store for read-only commands #47 passed