Add deep linking support for state issues, and handle out-of-state issues

[dektar]

we could also handle deep links for /state/ eventually.

Right now, /state/ will not work if the user isn't in that state because we don't have out-of-state issues returne din the app. Later, we should either fetch these dynamically when out-of-state, or show a link to go back to the web browser.

See for example https://5calls.org/state/utah/hb267-collective-bargining-ban-repeal/

[dektar]

We also have to handle hidden issues like https://5calls.org/issue/usda-reorganization-public-comment/

[scottpeterson]

The app only fetches issues for the user's state (?state=CA). If a California user taps a Utah issue link, it's not in the local list → shows "issue not found" error

No API method to fetch a single issue by slug regardless of state

Hidden/inactive issues (not in the main list) also fail the same way

The active field exists on the Issue model but is never checked

The URL pattern /state/utah/slug (without /issue/ prefix) doesn't match the current intent filter (pathPrefix="/issue/" in the manifest)

This is really 3 sub-problems:

1. Manifest fix: Add intent filter for /state/ path prefix (trivial)
2. API gap: Need a way to fetch a single issue by slug/permalink (requires backend support or a new endpoint)
3. UX decision: When an issue isn't found locally, what to show?