Modernize plugin interface

[user1303836]

Summary

• replace the legacy editor with a fixed 1000 x 640 technical dark interface while keeping all 20 existing parameters visible and APVTS-backed
• add truthful last-processing, learning-armed, topology, and Delta Audition states without changing processor or DSP behavior
• add bundled Barlow Condensed typography, strict exact entry, fine/reset/keyboard paths, complete accessibility metadata, and safe gesture teardown
• add production-linked UI/render tests, 100-200% scale evidence, per-platform CI captures, and strictness-10 plugin validation

Validation

• CTest: 2/2 passed
• UI tests: 9 cases, 363 assertions passed
• pluginval 1.0.4 strictness 10: SUCCESS
• clap-validator 0.4.1: 32 passed, 0 failed, 1 pre-existing warning, 11 skipped
• Release VST3, CLAP, and Standalone targets built; VST3 and CLAP package simulation passed
• embedded VST3 and CLAP passes covered focus, exact entry, reset, fine drag, balanced gestures, host updates/state recall, reopen, and fixed sizing
• HDN UI review score: 16/16
• PluginProcessor.* and all Source/DSP/* files remain byte-identical to 5a5d344

Existing release debt

The UI design document records unchanged bundle-identifier, macOS CLAP/Standalone signing, random-state validator, and pinned-wrapper gui.hide behavior. This PR intentionally preserves product identity and does not broaden a UI-only change into release-signing or wrapper work.

[user1303836]

Release verification is complete for e25cb7e.

• All 10 PR checks passed on macOS, Windows, and Linux: DSP tests, VST3/CLAP builds, validator jobs, and distribution packaging.
• VST3 passed pluginval 1.0.4 at strictness 10 on all three platforms.
• CLAP validation reported 0 failures on all three platforms (the documented pre-existing metadata warning remains).
• All 15 UI evidence captures (100%, 125%, 150%, 175%, 200% on each platform) were downloaded and inspected; renders are complete and opaque. The rerun artifacts are byte-identical to the prior exact-head captures.
• All six packaged VST3/CLAP ZIPs passed archive integrity checks.
• Local final-head CTest passed 2/2; the production-linked UI suite remains 9 cases / 363 assertions.
• All 13 protected PluginProcessor.* and Source/DSP/* files remain byte-identical to baseline 5a5d344.

CI: https://github.com/user1303836/suppressor/actions/runs/31129908530

Release verdict: SHIP. Bundle metadata/signing and the pinned-wrapper gui.hide behavior remain explicitly tracked non-UI follow-ups.

[user1303836]

README screenshot follow-up is complete at d4e61fb.

The approved docs/images/suppressor-ui.png capture is now displayed below the CI badge, with descriptive alt text. The image URL was verified against the pushed branch.

All 10 current-head PR checks passed on macOS, Windows, and Linux: https://github.com/user1303836/suppressor/actions/runs/31135150993