🐛 Mobile | Show reward details for unaffordable rewards

[jernejk]

1. What triggered this change? (PBI link, Email Subject, conversation + reason, etc)

✏️ Closes #1560

Adam Cogan reported that unaffordable reward records could be tapped but appeared to do nothing. This PR makes those taps open the reward detail view, show the large image, and explain the user's points shortfall instead of failing silently.

⚠️ TODO: Ask Tiago for TinaCMS store (#1557). Until Tiago confirms the store URL/copy, the purchase prompt is shown without an external link.

2. What was changed?

1. Reward list and carousel items now open the reward detail view even when the redeem action is disabled.
2. The reward detail view now receives the user's current balance and shows an unaffordable state with the points shortfall.
3. The unaffordable state shows the large reward image, hides the redeem form/actions, and includes the requested purchase prompt.

Figure: Before - tapping the unaffordable TinaCMS plushie stayed on the Redeem list.

Figure: After - tapping the same item opens the detail view with the large image and points message.

Figure: After - the Redeem list shows the corrected TinaCMS reward names.

3. Did you do pair or mob programming?

✏️ Yes - JK pairing with Codex.