Target-size compression had only a coarse DPI lever, so it undershot badly (a 350KB target could land at 216KB) and silently missed unreachable targets. Adds JPEG quality as a second lever (forced re-encode so it bites on JPEG scans), folds both into one monotonic quality axis that target-size binary-searches, reports targetMet honestly in the panel across 21 locales, and flips the tool to async for the extra passes. Quality-mode output sizes shift intentionally (slider now drives JPEG quality at full resolution in its top half).
#276's overhauled integration tests + QA sweep scripts hit the old
sectionless /api/v1/tools/<id> routes, which 404 after #280 made routes
section-prefixed. Ran scripts/rewrite-tool-paths.ts for literal URLs and
converted dynamic /api/v1/tools/${id} constructions to apiToolPath().
Negative-test paths (nonexistent/fake tools) intentionally left raw.
