Cortex v0.1.8

What's Changed

• fix(install): detect windows arch without OSArchitecture by @echobt in #16
• fix(tui): welcome splash, alt-screen, unavailable, mcp and plugins by @echobt in #17
• fix(tui): default alternate screen to always by @echobt in #18
• fix(tui): /model effort radios Low|Medium|High + Tab by @echobt in #19
• feat(tui): lock v2 runtime chrome by @echobt in #21
• docs(tui): add tui lock v2 design pack (boards + spec) by @echobt in #20
• feat(readiness): add quality gates and harden local runtime by @echobt in #22
• chore: bump version to 0.1.8 by @echobt in #33

Full Changelog: v0.1.7...v0.1.8