Fix Meet visual: reject solid avatar tiles + screen-share OCR

Root cause of the "4 people → 2 speakers" Meet call: the colored-border detector
read solid camera-off avatar tiles (orange "J", magenta "G") as active speakers
for the ENTIRE call. Those whole-call phantom spans dominated backend name
attribution, collapsing every remote voice onto one name — and the giant filled
bbox also swallowed screen-share text (WERUNBTC.COM ×49) as a speaker.

Validated against 9 real fixtures (harness over the real MeetAdapter):

Detection:
- FrameSampler.thinColoredPoints: coloured counterpart of thinWhitePoints — keeps
  thin border/ring/pill edges, drops solid colour fills.
- GridCallAnalyzer.isHollow: reject a highlight component whose interior is filled
  (a solid tile) vs a hollow ring (a real border). Config.maxInteriorFill (0.2 default).
- MeetAdapter: detect thin BLUE edges only (hue 180–240°, measured from the
  fixtures), maxInteriorFill 0.3 (real Meet rings ≈0.2–0.3, solid tiles ≈0.36).
- Result on fixtures: John Arnold/Grant Gilliam (solid tiles) now NEVER detected;
  Matt Odell/Mark detected when their blue cue is present. Sparse but never wrong —
  correct for a naming hint over audio diarization.

OCR name hygiene:
- isLikelyName rejects domain-like screen-share text ("WERUNBTC.COM", OCR'd ".GOM").
- cleaned() strips trailing punctuation ("Mark." → "Mark").
- TimelineBuilder.canonicalizeByFrequency folds rare OCR misspellings into a
  dominant near-twin name ("Matt Odel"/"MattOdell" → "Matt Odell", "Mare" → "Mark").

Tests: hollow-ring, extended OCR filter, fuzzy-merge. 65 pass.

Ten31Transcripts/Visual/FrameSampler.swift

@@ -120,6 +120,43 @@ struct FrameSampler {
         return points
     }
 
+    /// Grid-sampled saturated pixels that lie on a THIN structure (a non-saturated
+    /// pixel within `edgeGap` on some axis) — the coloured counterpart of
+    /// `thinWhitePoints`. This keeps a thin speaking BORDER/ring/pill but drops the
+    /// solid interior of a colour FILL (e.g. Meet's orange/magenta camera-off avatar
+    /// tiles), whose pixels are surrounded by the same colour. Pair with `hueRange`
+    /// to keep only the cue's colour (Meet's blue ring) and reject the thin edges a
+    /// solid tile still has against the background (orange/magenta boundaries).
+    func thinColoredPoints(threshold: Double = 0.35, minBrightness: Double = 60,
+                           hueRange: ClosedRange<Double>? = nil,
+                           edgeGap: Int = 6, gridStep: Int = 4) -> [CGPoint] {
+        func isCue(_ x: Int, _ y: Int) -> Bool {
+            guard x >= 0, x < width, y >= 0, y < height else { return false }
+            let i = (y * width + x) * 4
+            let r = Double(pixels[i]), g = Double(pixels[i + 1]), b = Double(pixels[i + 2])
+            let mx = max(r, g, b), mn = min(r, g, b)
+            let sat = mx > 0 ? (mx - mn) / mx : 0
+            guard sat > threshold, mx > minBrightness else { return false }
+            if let hr = hueRange { return hr.contains(Self.hueDegrees(r, g, b, mx, mn)) }
+            return true
+        }
+        var points: [CGPoint] = []
+        var y = edgeGap
+        while y < height - edgeGap {
+            var x = edgeGap
+            while x < width - edgeGap {
+                if isCue(x, y) {
+                    let thin = !isCue(x - edgeGap, y) || !isCue(x + edgeGap, y)
+                        || !isCue(x, y - edgeGap) || !isCue(x, y + edgeGap)
+                    if thin { points.append(CGPoint(x: x, y: y)) }
+                }
+                x += gridStep
+            }
+            y += gridStep
+        }
+        return points
+    }
+
     /// HSV hue in degrees (0…360) from RGB and its precomputed max/min channels.
     private static func hueDegrees(_ r: Double, _ g: Double, _ b: Double, _ mx: Double, _ mn: Double) -> Double {
         let d = mx - mn