CMRT 31: Fixups addCmrtMember + stem canonical pref + Clear MusicBrainz Data + CMRT/MBQueue refresh fix + MBQueue status text/rendering fix

[Swarnadip-Kar]

Five items bundled into one PR -- two flagged
fixups, one new preference, one new track-menu action,
one refresh bug fix.

A — Fixups

addCmrtMember()'s null-or-value binding restructured into temp
variables (mentor-suggested pattern).

B — Stem-aware canonical scoring

New preference (off by default): "Allow stem files to become the
canonical track (CMRT)." QualityScorer's format table doesn't recognize
"stem" as a filetype and was defaulting stems to the mp3-tier
score (50.0) -- letting a stem win or tie a canonical
election. Off, a stem's score is clamped to 0.0, so any real-format
competitor always outscores it, and two competing stems tie at 0.0 (the
existing ">" comparison already keeps whichever got there first -- no new
branching needed). The first track fingerprinted for any mastering still
always becomes canonical regardless of stem-ness; this only changes what
happens when a second track later matches into its group.
but the clamp is now comparison-only.

A stem's real QualityScorer score is always written to
cmrt_members/fingerprint_metadata -- the 0.0 clamp only ever decides who
wins a canonical election, it is never what gets stored for either
track. This was a correctness bug in the original draft: as written, a
stem's true score would have been overwritten with 0.0 in the database
itself.

C — Clear > MusicBrainz Data

New TrackDAO::clearMusicBrainzData() nulls every MBID/AcoustID column
(including acoustid_lookup_at, which updateAcoustIdResult() can't null --
it stamps that column with the current time unconditionally). Recovers
tracks whose lookup status is stuck at 'completed' with partially-correct
MBIDs, which were previously invisible to both the MBQueue view and the
worker's polling query. New WTrackMenu action mirrors Clear > Fingerprint;
standalone use re-queues for a fresh lookup, Clear > All does not (the
fingerprint is already gone by that point in the same action).

D — CMRT column refresh fix

The CMRT column comes from library_view's own joined SQL, cached once per
BaseSqlTableModel::select() -- unlike key/bpm (BaseTrackCache-backed),
it doesn't refresh on a plain dataChanged() signal, which is why it only
ever updated after an action that happens to trigger a full re-select
(sorting, switching sidebar tabs, toggling a column). Added
AcoustIdWorker::cmrtDataChanged(), emitted after each
CmrtGroupingService::processTrack() call, forwarded (signal-to-signal)
through a matching TrackCollectionManager::cmrtDataChanged() signal into
Library's existing slotRefreshLibraryModels() -- the same slot already
used for libraryScanFinished(), not a new refresh mechanism.
DlgPrefFingerprint::slotClearAllFingerprints() and
WTrackMenu::clearFingerprintDataForSelection() (Clear > Fingerprint /
Clear > All) had the identical stale-column problem and are fixed the
same way. The MBQueue panel had the same class of bug for a different
table (musicbrainz_queue_view, not the CMRT column) -- forwarded the
worker's existing queueDrained() through a new
TrackCollectionManager::acoustIdQueueDrained() signal so
DlgMusicBrainzQueue can re-select its own table model once per finished
batch instead of only on button clicks.

E — MBQueue Status column text fix

Separate, non-refresh bug found while reviewing the MBQueue files:
MusicBrainzQueueTableModel::rawValue() only mapped the NULL status case
to "pending" and passed every other status ("queued"/"failed"/
"unmatched") straight through as raw DB tokens, even though the comment
in AcoustIdWorker::processJob() explicitly says the view is supposed to
show "no match" vs "lookup failed" as distinct, readable text. Added the
missing mapping.

E-followup — MBQueue Status column rendering fix

The Status cell was rendering inside a boxed/bordered shape with a
leading gap before the text, unlike other columns. Root cause:
BaseTrackTableModel::roleValue() returned rawValue unconditionally for
columns mapping to COLUMN_LIBRARYTABLE_INVALID (i.e. columns whose name
isn't in ColumnCache::kColumnPropertiesByEnum, like "status"). For
Qt::DecorationRole, this caused Qt to interpret the status text string
as a decoration icon, rendering an empty black rectangle with reserved
space. Fixed in basetracktablemodel.cpp by guarding the early return to
only pass rawValue for display/tooltip/edit/export roles.

Depends on: cmrt-fixup-per-field-toggles-quality-score (#41)

[coveralls]

Coverage Report for CI Build 29038011575

Coverage decreased (-0.02%) to 30.227%

Details

• Coverage decreased (-0.02%) from the base build.
• Patch coverage: 94 uncovered changes across 10 files (1 of 95 lines covered, 1.05%).
• 12 coverage regressions across 7 files.

Uncovered Changes

File	Changed	Covered	%
src/musicbrainz/cmrtgroupingservice.cpp	22	0	0.0%
src/widget/wtrackmenu.cpp	19	0	0.0%
src/library/dao/trackdao.cpp	13	0	0.0%
src/library/dao/trackfingerprintdao.cpp	10	0	0.0%
src/library/musicbrainzqueue/musicbrainzqueuetablemodel.cpp	9	0	0.0%
src/preferences/dialog/dlgpreffingerprint.cpp	7	0	0.0%
src/library/basetracktablemodel.cpp	5	0	0.0%
src/library/musicbrainzqueue/dlgmusicbrainzqueue.cpp	4	0	0.0%
src/musicbrainz/acoustidworker.cpp	3	0	0.0%
src/library/trackcollectionmanager.cpp	2	0	0.0%
Total (11 files)	95	1	1.05%

Coverage Regressions

12 previously-covered lines in 7 files lost coverage.

File	Lines Losing Coverage	Coverage
src/musicbrainz/cmrtgroupingservice.cpp	4	0.0%
src/preferences/dialog/dlgpreffingerprint.cpp	2	0.0%
src/widget/wtrackmenu.cpp	2	0.0%
src/library/dao/trackfingerprintdao.cpp	1	0.75%
src/library/musicbrainzqueue/dlgmusicbrainzqueue.cpp	1	0.0%
src/library/musicbrainzqueue/musicbrainzqueuetablemodel.cpp	1	0.0%
src/library/trackcollectionmanager.cpp	1	25.15%

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Coverage Stats

Relevant Lines:	117108
Covered Lines:	35398
Line Coverage:	30.23%
Coverage Strength:	58785.87 hits per line

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💛 - Coveralls