# Link in Bio Page

## Objective

Give each user one shareable mobile page of links behind a handle they choose.

A public single-page list of a user's links, served from a chosen handle and editable without a deploy.

## Before You Begin

This feature is being added to an application that already exists and already
works. Do not scaffold a new project, and do not assume a blank slate.

Inspect the codebase first and establish:

- The existing application structure and where code of this kind already lives.
- The framework and version in use.
- The existing design system — colours, spacing, typography, and component conventions.
- Existing UI components you can reuse instead of writing new ones.
- The existing database structure, if this feature needs to persist anything.
- The existing authentication and authorization system, if this feature is user-scoped.
- Dependencies already installed, so you don't add a library that duplicates one.
- The existing test setup and conventions.

Only start writing code once you understand the above. If the application
already implements part of this feature, extend it rather than replacing it.

## Implementation Instructions

1. Reuse whatever handle or username the app already assigns for public profile pages instead of introducing a second namespace. Two independent handle systems will eventually collide on the same path.
2. Reserve system paths and obvious impersonation risks before opening handle selection, and check the reserved list on every rename rather than only on creation.
3. Design for a phone first and for slow connections. The page must render its links from the server with no client-side data fetch, because it will be opened inside social app browsers that block or delay scripts.
4. Reuse the app's existing scheduled publishing behaviour for links that should appear or expire on a date, rather than writing a second scheduler for this one page.
5. Do not build a general-purpose page builder here. Ship a heading, an avatar, an ordered list of link tiles, and a small set of theme choices, and defer arbitrary blocks and custom layout.

## UI and UX Requirements

Match the application's existing design system exactly. Reuse its components,
spacing, and typography. This feature should look like it was always there.

## Responsive Requirements

Works on mobile, tablet, and desktop. Touch targets are large enough to hit on a
phone, and nothing overflows horizontally at 320px.

## Accessibility Requirements

- Fully keyboard navigable.
- Correct semantic elements and ARIA roles.
- Visible focus states.
- Meets WCAG AA contrast.
- Dynamic changes are announced to screen readers.
- Respects prefers-reduced-motion.

## Edge Cases

- Handles need a reserved word list covering system routes, support and admin names, and anything that reads as official. Freeing a handle after an account is deleted invites squatting on a name people already trust, so hold it for a period before release.
- Scheduled links must appear and disappear on time in the visitor's experience even if the page is cached, which means the cache key or the render has to account for the schedule boundary.
- Click counts are inflated by social platform link previewers fetching every URL on the page. Filter known preview and bot traffic before counting, and never present raw hits as human clicks.
- In-app browsers strip styles, ignore some navigation, and sometimes block outbound links. Keep the layout functional with no custom styling applied and make every tile a plain link that works without interception.
- A deleted or unreachable destination leaves a broken tile on a live page. Check destinations periodically and flag or hide dead links for the owner rather than silently serving them.
- The page is public and user-generated, so it will be used for spam and phishing. Run new and edited destinations through the app's existing content reporting and moderation path, and give visitors a way to report a page.
- The avatar and any tile images need reserved dimensions and alt text, or the list will jump under a thumb already reaching for the first link.
- Renaming a handle breaks every share of the old one. Redirect the previous handle to the new one for a period and tell the owner that is happening.

## Testing

Exercise the feature end to end in the running application. Cover every edge case
above, then run the existing test suite and confirm nothing regressed.

## Acceptance Criteria

- [ ] Each page is served from a unique handle validated against a reserved word list on create and on rename.
- [ ] The page renders fully from the server and remains usable with scripts and custom styles blocked.
- [ ] Scheduled links appear and expire at their configured times even on a cached page.
- [ ] Click counts exclude known previewer and bot traffic.
- [ ] Links to unreachable destinations are detected and reported to the owner.
- [ ] Visitors can report a page, and reports land in the existing moderation path.
- [ ] A renamed handle redirects from its previous value.
- [ ] The feature matches the existing design system.
- [ ] No existing functionality is broken.

## Adaptation Rules

- Match the existing design system. Do not introduce a new colour palette,
  spacing scale, or component library.
- Reuse existing components and utilities wherever they fit.
- Follow the naming, file layout, and code style already present.
- Do not upgrade, replace, or remove existing dependencies to make this
  feature fit. Adapt the feature to the app, not the app to the feature.
- Do not break existing functionality. If a change is genuinely required in
  existing code, make the smallest one that works and say so.
- If something in these instructions conflicts with how the application is
  built, follow the application and explain the deviation.

## Final Verification

Before you report the work as done:

1. Re-read the acceptance criteria above and check each one against what you
   actually built.
2. Run the application and exercise the feature end to end.
3. Run the existing test suite and confirm you have broken nothing.
4. Check the feature on mobile, tablet, and desktop widths.
5. Check keyboard navigation and focus handling.
6. Summarize what changed: files added, files modified, and anything you
   deliberately did differently because of how this application is built.

If any acceptance criterion is unmet, fix it before reporting completion.