Donations Block: admin defaults (frequency/amounts/toggles)

[angelablake]

Stacked on top of #48415. Reviews can wait until that lands; this PR can be tested on Jetpack Beta in parallel.

Proposed changes

Adds admin-configurable frequency visibility controls and donation defaults to the Donations Form block.

Frequency visibility toggles

• New "Show one-time donations" toggle in the Settings panel, joining the existing monthly and annual toggles, so authors can hide any combination of intervals.
• Last-enabled guard: the final visible toggle is disabled and shows help text ("At least one frequency must be enabled."), preventing an empty/broken form.
• Auto-shift: hiding the interval that is currently set as the default silently shifts defaultInterval to the next visible interval in the same setAttributes call — no stale or invisible default can persist.
• Side-effect bug fix: previously, hiding One-Time while keeping Monthly broke the frontend — view.js was hardcoded to this.interval = 'one-time'. The fix reads the initial interval from data-default-interval on the wrapper instead.

Frequency and amount defaults

• New "Defaults" sub-section in the Settings panel with a Frequency selector (filtered to currently-shown intervals) and per-frequency default amount selects (None + the three configured dollar values).
• Default amount is stored by index, not value, so it survives admin edits to the amount values (e.g. changing $15 → $20 keeps the same slot pre-selected).
• Suggested custom amount: a number input for the placeholder value shown in the custom amount tile; currency-aware minimum enforced.
• On load and on each tab switch, the configured default amount tile is highlighted and the Donate button is pre-enabled. Clears and resets correctly when switching tabs.
• Currency change resets customAmountPlaceholder along with the existing per-interval amount reset.

Related product discussion/links

• Part of the same internal RSM project as #48415.

Does this pull request change what data or activity we track or use?

No tracking or data changes.

Testing instructions

Frequency toggles

1. Add a Donations Form block. In the Settings panel, toggle "Show one-time donations" off.
   • The One-Time tab should disappear in the editor; the active tab should fall back to Monthly (or Yearly if Monthly is also off).
   • Save and view on the frontend — the One-Time tab should be gone.
2. Toggle off Monthly as well — only Annual remains. Confirm all three toggle buttons show the last-enabled help text and are disabled, preventing an empty form.
3. Toggle One-Time back on — the tab reappears and the block is functional again.
4. Open a legacy Donations block (created before this branch, where oneTimeDonation.show was never set) — the One-Time toggle should show as on and the block should behave normally.

Defaults section [screenshot]
5. Expand the Settings panel and locate the Defaults sub-section below the Show/hide toggles.

• Set Frequency to Monthly and Monthly default amount to the $15 slot.
• Save and view on the frontend — the Monthly tab should be active on load, with the $15 tile pre-selected and the Donate button enabled without any user interaction. [demo]

6. Set a suggested custom amount (e.g. 50) — the custom amount tile placeholder on the frontend should reflect this value.
7. Change currency — the suggested custom amount should reset.
8. Hide the frequency that is set as the default — the default should automatically shift to the next visible interval without requiring a separate action.

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Recreated as a successor to #48464, which auto-closed when its base branch was deleted on merge of #48415. Same content; rebased onto trunk as a single squashable commit.

[github-actions]

Are you an Automattician? Please test your changes on all WordPress.com environments to help mitigate accidental explosions.

• To test on WoA, go to the Plugins menu on a WoA dev site. Click on the "Upload" button and follow the upgrade flow to be able to upload, install, and activate the Jetpack Beta plugin. Once the plugin is active, go to Jetpack > Jetpack Beta, select your plugin (Jetpack), and enable the update/donations-frequency-amount-defaults branch.
• To test on Simple, run the following command on your sandbox:

bin/jetpack-downloader test jetpack update/donations-frequency-amount-defaults

Interested in more tips and information?

• In your local development environment, use the jetpack rsync command to sync your changes to a WoA dev blog.
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[github-actions]

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Code Coverage Summary

Coverage changed in 5 files.

File	Coverage	Δ%	Δ Uncovered
projects/plugins/jetpack/extensions/blocks/donations/controls.js	0/58 (0.00%)	0.00%	30 💔
projects/plugins/jetpack/extensions/blocks/donations/donations.php	117/355 (32.96%)	-2.39%	24 💔
projects/plugins/jetpack/extensions/blocks/donations/view.js	0/123 (0.00%)	0.00%	19 💔
projects/plugins/jetpack/extensions/blocks/donations/tabs.js	0/28 (0.00%)	0.00%	9 💔
projects/plugins/jetpack/extensions/blocks/donations/utils.js	0/10 (0.00%)	0.00%	4 💔

Full summary · PHP report · JS report

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