Record DonorPerfect gifts once, with valid codes

**Objective:** Record a gift of `{amount}` from `{donor-name-or-email}`, dated `{gift-date}`, against campaign `{campaign}` if one is given. Resolve the donor and validate every code before writing anything.

**Step 1: Identify the donor**

Call `donorperfect-get-donor`, filtering on `email` if `{donor-name-or-email}` is an email address and on `last-name.contains` otherwise. If no donor matches, or more than one does, report the candidates and stop. Do not create a donor. Record the `donor-id`.

**Step 2: Validate the codes**

If `{campaign}` was supplied, call `donorperfect-get-code` with `field-name` set to the campaign field and confirm the value exists. If it does not, list the closest valid codes and stop.

Do the same for any GL or solicitation code the user asks for. Never invent a code value.

**Step 3: Check for a duplicate**

Call `donorperfect-get-gift` filtered by `donor-id` and by `gift-date.from` and `gift-date.to` covering `{gift-date}`. If a gift of the same amount already exists on that date, show it, say it looks like a duplicate, and stop.

**Step 4: Confirm, then write**

Show the exact gift you are about to record: donor name and id, amount, date, campaign, record type. Ask the user to confirm in plain words.

Only after the user confirms, call `donorperfect-save-gift` exactly once, with no `gift-id` so that a new gift is created.

**Step 5: Verify**

Call `donorperfect-get-gift` filtered by `donor-id` and the gift date, and report the stored gift back with its `gift-id`.

**Rules & Guidelines:**

* `donorperfect-save-gift` is the only write tool this prompt may call, and it may be called once.
* Never supply a `gift-id`. Updating an existing gift is out of scope here.
* If the donor does not exist, stop. Do not call `donorperfect-save-donor`.

**Validation:**

* If `{amount}` is not a plain number, or `{gift-date}` is not a clear date, ask for it again and stop.
* If the user does not confirm, write nothing and say so.