feat(chat): Admin UI for invitation redirect URIs

[ChrisPdgn]

What kind of change does this PR introduce? (check at least one)

• Bugfix
• Feature
• Code style update
• Refactor
• Build-related changes
• Other, please describe:

Does this PR introduce a breaking change? (check one)

• Yes
• No

The PR fulfills these requirements:

• It's submitted to the master branch
• When resolving a specific issue, it's referenced in the PR's title (e.g. fix #xxx, where "xxx" is the issue number)

If adding a new feature, the PR's description includes:

• A convincing reason for adding this feature (to avoid wasting your time, it's best to open a suggestion issue first and wait for approval before working on it)

Other information:

Draft Admin UI for Chat invitation redirects so operators can configure the login / accept / decline destinations that Conduit chat invitation emails now depend on. Without these fields, the admin panel cannot persist explicit_room_joins.redirect and unauthenticated email-link clicks fail until login_uri is set.

This is a draft PR against ui-rewrite. Do not mark ready or merge until backend Conduit #1512 lands and the form is verified against a live Chat config that includes explicit_room_joins.redirect.

Summary

Chat Settings now exposes three invitation redirect URI inputs that map 1:1 to Conduit explicit_room_joins.redirect:

Admin field	Config key	Behavior
Login Redirect URI	login_uri	Absolute login page for unauthenticated email-link clicks. The hook appends ?redirectUri=...&answer=...&invitationToken=... so login can return to the hook. Empty means those clicks fail until configured.
Accept Redirect URI	accept_uri	Post-accept destination. Supports {roomId}. Empty returns JSON instead of redirecting.
Decline Redirect URI	decline_uri	Post-decline destination. Supports {roomId}. Empty returns JSON instead of redirecting.

Validation uses plain strings, not z.string().url(), so {roomId} placeholders are accepted. Missing redirect from older Chat config is merged to empty strings so RHF stays controlled. The optional Zod object also defaults to empty strings so patchChatSettings stays assignable to ChatSettings.

Existing explicit-join switches, ModuleToggle, and patchChatSettings are unchanged — the new object rides the same submit path.

Validation

Exercised on the ui-rewrite admin at Chat → Settings against a local Conduit 0.17 standalone (admin/admin):

• Invitation Redirects section renders under the switch grid with the three labeled fields and descriptions.
• Inputs stay disabled while "Require invite to join room" is off; they enable in Edit mode once that switch is on.
• https://example.com/chat/{roomId} is accepted (no URL-schema error).
• Save of the existing explicit_room_joins.enabled flag succeeds.
• GET /config/chat after save does not contain redirect — expected until Conduit #1512 is deployed. This 0.17 convict config has no explicit_room_joins.redirect keys, so those values are stripped server-side.

Test plan

• Open Chat → Settings with Chat serving
• With "Require invite to join room" off: Invitation Redirects heading/labels muted, inputs disabled
• Enable invite-required + Edit: all three URI fields become editable
• Form accepts accept_uri with {roomId} (no z.string().url() rejection)
• Save login_uri / accept_uri / decline_uri and confirm they persist after reload — blocked until Conduit #1512
• Save empty accept/decline URIs (allowed; backend returns JSON)
• Cancel / view mode leaves the existing switch grid and ModuleToggle path unchanged
• After Conduit #1512: unauthenticated email accept click redirects to login_uri?redirectUri=...

Related: ConduitPlatform/Conduit#1512