Filter OCR to participant-name labels (kill visual-timeline noise)

Real Meet capture revealed the visual pipeline was treating ALL on-screen text as
participant names: meeting URL, clock, 'Add others' button, lobby 'Your meeting's
ready' dialog, 'Joined as …@gmail.com', etc. 46 of 52 'visual segments' in a real
session were phantom speakers. (The backend was unaffected — it diarizes from audio
and ignores names that match no voice cluster — but the visual_timeline.json and the
segment count were junk.)

GridCallAnalyzer.isLikelyName now gates OCR strings to things shaped like a name:
2–30 chars, 1–3 Title-Cased alphabetic words, no digits/URL/email/glyph punctuation.
Errs toward dropping (a missed name just loses a hint; audio diarization still runs).
Unit-tested against the EXACT 19 OCR strings from the real session: keeps the 5
real names, drops all 14 chrome strings. 28/28 XCTest.

Ten31Transcripts/Visual/GridCallAnalyzer.swift

@@ -51,7 +51,7 @@ struct GridCallAnalyzer {
 
     func analyze(cgImage: CGImage, at t: TimeInterval) -> [SpeakerObservation] {
         let texts = recognizer.recognize(in: cgImage).filter {
-            $0.confidence >= config.minTextConfidence && !cleaned($0.text).isEmpty
+            $0.confidence >= config.minTextConfidence && Self.isLikelyName(cleaned($0.text))
         }
         guard !texts.isEmpty, let sampler = FrameSampler(cgImage: cgImage) else { return [] }
         let w = cgImage.width, h = cgImage.height
@@ -137,8 +137,29 @@ struct GridCallAnalyzer {
     }
 
     private func cleaned(_ s: String) -> String {
-        let t = s.trimmingCharacters(in: .whitespacesAndNewlines)
-        return t.count <= config.maxNameLength ? t : ""
+        s.trimmingCharacters(in: .whitespacesAndNewlines)
+    }
+
+    /// True if `s` looks like a participant name label rather than UI chrome. Call
+    /// UIs are full of text (meeting URLs, the clock, "Add others", lobby dialogs)
+    /// that OCR would otherwise treat as speakers. Participant labels are short,
+    /// Title-Cased, 1–3 alphabetic words with no digits/URL/email punctuation.
+    /// Derived from real Meet/Zoom captures; errs toward dropping (a missed name
+    /// just means no visual hint — the backend still diarizes from audio).
+    static func isLikelyName(_ s: String) -> Bool {
+        guard s.count >= 2, s.count <= 30 else { return false }
+        // Reject URLs, emails, meeting codes, times, button glyphs.
+        if s.rangeOfCharacter(from: CharacterSet(charactersIn: "@:/\\|+*=<>#0123456789")) != nil {
+            return false
+        }
+        let words = s.split(separator: " ")
+        guard (1...3).contains(words.count) else { return false }
+        let allowed = CharacterSet.letters.union(CharacterSet(charactersIn: "'.-"))
+        for w in words {
+            guard let first = w.first, first.isUppercase else { return false }   // Title Case
+            if String(w).unicodeScalars.contains(where: { !allowed.contains($0) }) { return false }
+        }
+        return true
     }
 
     private static let ciContext = CIContext()