[bmc08gt]

Edit Group now lets a group's creator change its Join and Chat minimums. Saving sends the group's full rule set through EditChat (EditChatParameters.rules), and every member's chat follows a rules change as it arrives.

Depends on #1876 (flipcash2 0.23.0 scaffolding), which adds EditChatRequest.rules and MetadataUpdate.RulesChanged.

Which groups can be edited
EditChatRequest.rules only accepts a public group created with a listener minimum: a private group is DENIED and any other group is INVALID_RULES. The Balance Requirements card is always shown, but its rows only open the keypad for such a group (isBalanceEditable). A rule this build can't decode (UnsupportedSpeakerRule) also makes the rows read-only, since sending the set back would have to drop it.

What gets sent

• The outgoing set starts from the group's current rules and changes only the edited minimum. Staff, creator and any other rules go back as they are (withMinimum, withoutSpeakerMinimum in shared/chat/GroupRulesEdit.kt).
• The listener rule keeps its currency and mints. A speaker rule takes the listener rule's mints and is stored in its currency, which isn't necessarily USD. The keypad entry is converted into that currency through USD and rounded to its decimals (minimumBalanceIn). This replaces the USD-only minimumBalanceFor.
• On success the Metadata from the response is stored, so the screen doesn't wait for the event.

Checked before sending

• Every amount is at least the currency's minimum transfer value ($0.01, ¥1). Below that, Save stays disabled.
• An amount equal to the current rule leaves Save disabled.
• A Chat amount at or below Join plus the minimum transfer value shows "Chat Minimum Too Low". A Join amount that would no longer sit below Chat shows "This Requirement Isn't Valid".
• When the caller's balances and rates are known, new minimums the creator doesn't meet show "You Don't Meet This Requirement". Only the minimum-balance rules are weighed; the server judges the rest.

Removing the Chat minimum. The Chat keypad has a Remove action in its app bar when the group has its own speaker rule. It sends the set without that rule, so speaking needs only joining. Without a speaker rule, the Edit Group Chat row shows the Join amount, as the profile does.

Server errors. RULES_NOT_SATISFIED shows "You Don't Meet This Requirement". INVALID_RULES shows "This Requirement Isn't Valid" and is reported to Bugsnag, as are other failures ("Couldn't Save the Requirement"). The Unavailable stub, its "Not Available Yet" copy and its test are gone.

The old known gap, where the Chat row treated the Join amount as its current value and saving it created a separate chat rule, is closed: a Chat amount at or below Join is now blocked before sending.

Rules changing live
RulesChanged was already mapped and stored through ChatMetadataDao.updateRules, and the in-chat consumers (subject, bottom bar, gate bars, holding label, profile card) read the stored row, so a member's chat follows it without reopening. A member who falls below a raised Join minimum stays in the group and keeps reading but loses speaking, the same state as when their balance drops.

RulesChanged only reaches members, so this adds ChatCoordinator.refreshRules (a GetChat that stores only the rules) for the places it doesn't:

• when the viewer is found outside a stored group, as after a leave, so rejoining is judged against current rules;
• after a join fails with RULES_NOT_SATISFIED;
• when a non-member opens Group Info.

Tests. EditGroupBalanceRequirementViewModelTest covers each rule above. GroupRulesEditTest covers editability and the rule-set builders. ChatMetadataDaoTest and the mapper tests show rules_json round-trips a speaker rule being added and removed, and that the stored chat re-emits on updateRules. GroupFeedDelegateTest covers refreshRules.