chore: extract ShareServer into its own repository

Move the existing Hono API, React console, tests, build configuration,
and feature documentation from GoodBuddy into a standalone project.
Keep the current interactive-prototype behavior and production limitations.

Document the source commit and sibling-checkout links to the authoritative
Desktop network architecture. Independent install, tests, typecheck, lint,
build, and built-service HTTP smoke checks passed.

AGENTS.md

@@ -0,0 +1,45 @@
+# ShareServer Agent Guide
+
+## Scope and product status
+
+This repository owns the independent ShareServer API and Web console.
+The current implementation is an interactive prototype, not a production
+identity, authorization, persistence, or task-routing service. Preserve this
+distinction in code, UI, documentation, and validation reports.
+
+## Implementation
+
+- Follow the existing TypeScript, Hono, React, Vite, and local UI components.
+- Keep the service independently buildable. Do not import Electron or files
+  from the GoodBuddy Desktop checkout.
+- Use KISS and YAGNI. Do not add speculative recovery or security frameworks.
+- Preserve user work and never commit credentials, local data, or generated
+  output. Do not publish or push unless explicitly requested.
+- Keep user-facing copy primarily in Simplified Chinese.
+- Preserve cancellation, error context, accessibility, and prototype boundaries.
+
+## Documentation
+
+- `docs/features/share-server/README.md` is the feature entry point.
+- PRD owns requirements; logic design owns state rules; UI design owns
+  interactions; technical design owns implementation contracts; progress owns
+  dated, verified facts. Do not duplicate their authoritative definitions.
+- Update affected documentation when changing functionality.
+- Cross-product network architecture remains in the adjacent GoodBuddy
+  repository, as linked from the root README. Do not copy it into this repo.
+- Consult the linked GoodBuddy UI design system before UI changes, while
+  retaining the independent Web shell and existing local components.
+
+## Validation
+
+Run `npm ci` for a fresh checkout, then:
+
+```text
+npm test
+npm run typecheck
+npm run lint
+npm run build
+```
+
+Validate affected behavior through the running service and UI when applicable.
+Mocks and prototype acknowledgements do not establish production readiness.