feat: add userscript task progress and fix resource card overlap

[anobaka]

Userscripts now show completed, failed and total task counts above the settings button: ExHentai download tasks and SoulPlus/NorthPlus post-parsing tasks. The panel can be dismissed and restored in settings, and opens the corresponding unfiltered task page in a new tab. Compact source-specific endpoints refresh while the page is visible; parser counts respect running workflows, partial results and purchase requirements. Userscript build and bundle tests now gate the existing required frontend check.

Resource cards also remeasure their actual height after deferred content updates, fixing overlap on direct resource-tab refresh.

Validation:

• 27 userscript tests and TypeScript/production build passed.
• 22 focused backend tests passed, including real HTTP summaries and source/status isolation; SDK regenerated.
• 54 resource regression tests passed; full Docker source build passed.
• Existing local Docker updated to 2.4.0-beta.565 with script 2.1.2; mounts, identities and delivered assets verified. Both panels, close/reload persistence, settings restoration and unfiltered new-tab links verified with the deployed bundle and real APIs in a temporary local harness. The browser's Tampermonkey user-script permission is disabled, so extension execution was not used for UI verification.

Fixes #1581
Closes #1582