Fix picospinner migration issues, clean up Logger API

[fredrikekelund]

Related issues

• Related to Replace ora with picospinner #3035

How AI was used in this PR

Not at all.

Proposed Changes

#3035 migrated from the ora library to picospinner. There are some subtle differences in how these two libraries behave that weren't addressed there, and this PR tackles them.

1. picospinner throws if we call .start() when the spinner is already running. Fix 'Spinner is already running' error when creating sites via CLI #3093 fixed that for the site create command specifically, but this PR generalizes the fix so we can safely call any Logger method without worrying about a crash.
2. With ora, the Logger.reportSuccess method would log a new success line. This behavior disappeared in Replace ora with picospinner #3035, which removed some messages from the logging output. This PR brings back that behavior.

Lastly, I removed the shouldClearSpinner argument from the Logger.reportSuccess method. This was introduced in #1306 to address some CfT feedback on the first version of the CLI, but the better solution is to just not call Logger.reportSuccess at all (which is what we've been doing in most new code we've added since then).

Testing Instructions

1. npm run cli:build
2. node apps/cli/dist/cli/main.mjs export --path PATH_TO_SITE and ensure the command completes successfully
3. node apps/cli/dist/cli/main.mjs preview create --path PATH_TO_SITE and ensure the command completes successfully
4. node apps/cli/dist/cli/main.mjs site create and ensure the command completes successfully

Pre-merge Checklist

• Have you checked for TypeScript, React or other console errors?

[fredrikekelund]

The non-null assertions on progressCallback were superfluous, so I took this opportunity to remove them.

[wpmobilebot]

📊 Performance Test Results

Comparing 16fb816 vs trunk

app-size

Metric	trunk	16fb816	Diff	Change
App Size (Mac)	1282.23 MB	1282.23 MB	0.00 MB	⚪ 0.0%

site-editor

Metric	trunk	16fb816	Diff	Change
load	1556 ms	1893 ms	+337 ms	🔴 21.7%

site-startup

Metric	trunk	16fb816	Diff	Change
siteCreation	8109 ms	8128 ms	+19 ms	⚪ 0.0%
siteStartup	4306 ms	4315 ms	+9 ms	⚪ 0.0%

---

Results are median values from multiple test runs.

Legend: 🟢 Improvement (faster) | 🔴 Regression (slower) | ⚪ No change (<50ms diff)

[bcotrim]

LGTM and works as expected 👍