feat: add IMAX badge and fix DV false-positive detection (#118)

[ProdigyV21]

Summary

Closes #118.

Adds an IMAX badge to stream source entries and fixes a long-standing false-positive where SD DVDrip sources were being incorrectly flagged as Dolby Vision.

Root cause

Two bugs in CompactQualityBadge in StreamSelector.kt:1010-1083:

1. DV false positives — The DV badge used:

   val isDV = quality.contains("DV", ignoreCase = true) || quality.contains("Dolby Vision", ignoreCase = true)

   Substring matching on "DV" matched everything containing those two letters, including "DVD", "HDVD", "DVDRip", "MediaDVx", etc. Standard-definition DVD rips were visually indistinguishable from true Dolby Vision sources in the picker.

2. No IMAX detection — IMAX was not in the badge list at all, despite being one of the most visually distinctive premium formats users explicitly scan for.

3. Narrow search scope — Both HDR and DV detection only looked at the pre-extracted stream.quality string. IMAX and DV tokens almost always live in the filename / source title (stream.source or stream.behaviorHints.filename), not the quality ladder slot.

Fix

1. Widen the search blob

CompactQualityBadge now takes the full StreamSource instead of just quality, and builds a single search blob:

val searchBlob = buildString {
    append(stream.quality)
    append(' ')
    append(stream.source)
    append(' ')
    append(stream.behaviorHints?.filename.orEmpty())
}

This way tokens are detected wherever they appear.

2. Word-boundary regex constants

Replaced contains(...) substring matching with pre-compiled \b-bounded regexes:

private val DV_REGEX = Regex("""\b(DV|DoVi|Dolby[\s._-]*Vision)\b""", RegexOption.IGNORE_CASE)
private val HDR_REGEX = Regex("""\bHDR(10\+?|10)?\b""", RegexOption.IGNORE_CASE)
private val IMAX_REGEX = Regex("""\bIMAX\b""", RegexOption.IGNORE_CASE)

• \bDV\b matches DV as a whole token but NOT DVD, HDVD, DVDRip.
• DoVi and Dolby.Vision / Dolby_Vision / Dolby-Vision / Dolby Vision still match.
• HDR regex also cleanly matches HDR10 and HDR10+ as the same badge.
• IMAX regex matches the standalone IMAX token.

Regexes are declared at file scope with val, so they're compiled once.

3. IMAX badge

Rendered in a distinctive cyan/blue (0xFF06B6D4) so it stands out from HDR (purple) and DV (pink). Only rendered when isIMAX is true, so non-IMAX sources get no extra space.

Test cases handled

Source title	Before	After
Movie.2021.1080p.DVDRip.x264.mkv	❌ shows DV badge	✓ no DV badge
Movie.2021.2160p.IMAX.WEB-DL.DV.HDR.mkv	only HDR shown	4K + HDR + DV + IMAX
Movie.2021.DoVi.Remux.mkv	❌ no DV badge (DoVi not in regex)	✓ DV badge
Movie.2021.Dolby.Vision.mkv	✓ (but for the wrong reason — substring match)	✓ (word-boundary match)
Movie.2021.HDR10+.mkv	✓ HDR badge	✓ HDR badge

Risk

Minimal. Single-file, 45-line change. Pure UI — no stream selection logic touched, no network calls, no settings, no cross-device state. The only API change is the internal helper signature (String → StreamSource), and there's only one call site which is updated in the same PR.