Add IIDX INFINITAS support with manual score entry

[katagaki]

Summary

Adds support for beatmania IIDX INFINITAS, the PC home version. Unlike the
arcade versions, INFINITAS has no e-amusement CSV/web export, so scores are
tracked manually.

INFINITAS is modeled as a new IIDXVersion (not the scaffolded
Game.iidxInfinitas), so it reuses the existing IIDX scores screen, score
viewer, and shared PlayData.db, with records tagged by version — exactly like
the arcade versions already coexist.

What changed

• Version picker — adds IIDXVersion.infinitas, ordered to appear last
  (bottom) in the version dropdown.
• Manual add — when INFINITAS is selected, the toolbar Import button is
  replaced by a + button that opens a new add/edit sheet.
• Editor (IIDXInfinitasScoreEditor) — add / edit / delete a single
  chart entry: title (with an optional BEMANIWiki-backed song-title
  picker), artist, genre, play type, level + rating, EX score / PGreat / Great /
  Miss, clear type, DJ level, last-played, and play count.
• Persistent collection — all manual entries live in one date-agnostic
  import group and are always visible regardless of the selected date; the
  time-travel control is hidden in INFINITAS mode.
• Score viewer — gains a bottom edit (pencil) toolbar for INFINITAS
  entries; saving updates in place, deleting pops back to the list.
• Row-id tracking — records now carry their SQLite row id (@Transient databaseID) so manual entries can be targeted for edit/delete.

Implementation notes

• New persistence helpers on IIDXImporter: infinitasImportGroupID,
  addManualSongRecord, updateSongRecord, deleteSongRecord (reusing the
  existing insertSongRecord column layout).
• IIDXReader.importGroup(for:version:) short-circuits to the single INFINITAS
  group, and its record cache always re-queries for INFINITAS so add/edit/delete
  reflects immediately.
• Each entry populates exactly one level; the other four are left empty.
• New localized strings added to Localizable.xcstrings (en + ja).

Verification

The remote environment is Linux with no Swift toolchain, so this was verified by
inspection rather than a build. Suggested manual checks in Xcode:

1. Version dropdown shows INFINITAS last; selecting it switches the IIDX
   scores screen into manual mode (Import → +, time-travel hidden).
2. Add an entry by hand and via the BEMANIWiki picker → appears in the list;
   persists across relaunch and date changes.
3. Open an entry → bottom pencil (verify iOS 18 Spacer and iOS 26
   ToolbarSpacer(.flexible)); edit updates, delete removes and returns to list.
4. Switch back to an arcade version → Import button and time-travel return;
   SOUND VOLTEX / Polaris Chord modes unaffected.

https://claude.ai/code/session_012v5AtjfrQSraHMhPRVmSid

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Generated by Claude Code

[sonarqubecloud]

Quality Gate passed

Issues
1 New issue
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
11.0% Duplication on New Code

See analysis details on SonarQube Cloud