Edit live Bitly links without losing tags or surprise redirects

**Objective:** Update the bitlink `{link}`: set the destination to `{new-long-url}`, the title to `{new-title}`, and add the tags `{add-tags}`. Only change what was supplied.

**Step 1: Identify the bitlink**

Call `bitly-get-bitlink` with `link` set to `{link}`. If nothing comes back, retry with the scheme added or removed (`https://bit.ly/abc` vs `bit.ly/abc`). If it still matches nothing, call `bitly-get-bitlink` with `title.contains` set to `{link}` instead. If more than one bitlink matches, list them (link, title, long-url, created-date) and stop so the user can pick one.

Note its `bitlink-id`, current `title`, `long-url`, `tags` and `archived` state.

**Step 2: Check the impact of a destination change**

If `{new-long-url}` is given:

* It must start with `https://` or `http://`; warn about `http://`.
* Call `bitly-get-click-day` with `link` for the last 30 days and report the clicks, so the user sees how much live traffic will be redirected.

**Step 3: Build and confirm the change**

* Tags: the new list is the current `tags` plus each tag in `{add-tags}` not already present. `bitly-update-bitlink` replaces the whole tag list, so always send the merged list, never just the new tags.
* Show a before and after table for every field that changes. Ask the user to confirm.

**Step 4: Update**

Call `bitly-update-bitlink` once with `id` = `bitlink-id`, and only the fields that change (`long-url`, `title`, `tags`).

**Step 5: Confirm the result**

Call `bitly-get-bitlink` with `link` again and show the stored values. Flag any field that does not match what was sent.

**Rules & Guidelines:**

* `bitly-update-bitlink` is the only write allowed, called once, after the confirmation in Step 3.
* Never send `archived` from this prompt; archiving is the job of `archive-dormant-bitlinks`.
* Never call `bitly-add-bitlink`.
* If the link is archived, say so and ask whether to continue before changing it.

**Validation:**

* If `{new-long-url}`, `{new-title}` and `{add-tags}` are all empty, ask what to change and stop.
* If the update fails, report the error verbatim and do not retry.