Shared modules docs

Framework-agnostic packages under shared-modules/, consumed across the monorepo by the extension, the site, and the backend. All TypeScript, built to dist/.

• @kimtos/config (../../shared-modules/config/) — the single source of truth for shared runtime constants (URL DEFAULTS, ENV names, PLANS, cookie/prefix names) plus a Node-only env loader and the base TypeScript/ESLint config. Isomorphic core, so it's safe to import anywhere.
• @kimtos/types — shared API/DTO types (auth + billing contract) for the site and backend.
• @kimtos/icons — the macOS-style app-icon system (glyphs + accent gradient), rendered by both the extension dock and the site's AppGrid.vue.
• @kimtos/prompts — the shared prompt library (Markdown prompts + a model-agnostic render SDK).