Play instruments when qualifying them, and add an omx-clap-host profile (#72)

[linuxnow]

Part of #72: the CLAP arm and the profile. Follow-ups filed under #72: #77 (LV2 instruments fed MIDI), #78 (cost with a chord held), #79 (the full classifier reads the note sweep; an instrument's latency is not an impulse mismatch).

What changes

• native/clap-qualify.c: a plugin with a note input is played at every rate under a count of its own, after the parameter sweep: a chord, pitch bend and CC 1 across a block, pressure, the chord off, a burst of 32 note ons in one block and their offs, all notes off, in the dialect its first note input reads (CLAP note events and expressions, else MIDI bytes). The line gains noteSweep (applicable, dialect, blocks, noteEvents, processErrors, nonFinite, interposer, and the three counts and events under the interposer). xruns are not measured: the prober is headless, as for the effect sweep.
• --offer <ext,...>: the prober also offers clap.preset-load/2, clap.track-info/1, clap.remote-controls/2 (host functions that answer nothing), and lists them in hostExtensions.
• Judge: noteSweepReasons beside clapRtReasons; new codes hosting.rt-safety.clean-under-notes, hosting.rt-safety.violations-under-notes, hosting.rt-safety.notes-unmeasured. A plugin with no note input gets none.
• Profile omx-clap-host: the console's six extensions plus the three above, instruments fed, shared process, latency uncompensated, LV2 features the console's in-process table (same provider), budget mod-host's (0.05 at 48000/128). qualifyClapTargets runs the prober once per offer the asked profiles need and judges each profile from its own run.
• Fixtures: synth.clap, synth-alloc.clap (malloc on note on), synth-midi.clap.

Schema change (additive, versioned): plugin-qualify.rt-safety/1 becomes plugin-qualify.rt-safety/2 = /1 + measured.noteSweep + the note sweep's reasons in verdict.reasons. Every /1 field is unchanged; an effect's /2 verdict equals its /1 verdict.

Reader contract for omx-plugins (tools/qualify-release.sh): it reads only verdict.rating and verdict.rtSafe, so it keeps working unchanged. Its comment and its self-test stub name /1; they should say /2, and the gate now refuses an instrument that allocates on a note even when its parameter sweep is clean. openmixer's locale tables need the three new hosting.rt-safety.* codes.

Tests (podman, worker image f05555bdca2de108 + jack/lv2 devel)

• Red before: origin/main's CLI on synth-alloc.clap reads suitable under openmixer-console. After: unsuitable, hosting.rt-safety.violations-under-notes, under both openmixer-console and omx-clap-host; synth.clap reads suitable under omx-clap-host.
• New tests: live note-sweep cases (clean, allocating, MIDI-only, an effect not played, no interposer, --offer and the omx-clap-host verdict, an unknown --offer refused), parse and verdict units, proberOffer, one run per offer, the profile held to omx-clap-core's clap_host_extensions.h and configure_core, and an instrument suitable under omx-clap-host and unsuitable under openmixer-console in the classifier.
• Sabotage by hand: the note sweep skipped in the prober: 4 red; the violations rule removed from noteSweepReasons: 2 red; restored: green.
• make -C native deps all asan, pnpm lint, pnpm check:generated, pnpm test:py (176 passed): green. CI=1 pnpm test: 444 passed, with PLUGIN_HOSTD pointed at a built daemon for pins-file.test.ts.

Not green, not mine: clap-loader.test.ts > 'walks the CLAP path as before when the LV2 path holds no bundle' is red in this image on origin/main too: it walks the image's /usr/lib/clap. Filed #80.