v5: refactor into modular stream_tools desktop app

Same inaSpeechSegmenter engine split into reusable core/ (fftools, segmenter, exporters) + utils/ and a CustomTkinter multi-tab UI. Adds JSON and ffmpeg-script export. Extracted from the stream_tools app.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

ui/theme.py

@@ -0,0 +1,64 @@
+"""
+Theme, DPI, and shared styling constants.
+"""
+
+import sys
+
+# ── DPI awareness (call before any Tk/CTk window) ────────────────────────────
+def setup_dpi():
+    if sys.platform == "win32":
+        try:
+            import ctypes
+            ctypes.windll.shcore.SetProcessDpiAwareness(2)
+        except Exception:
+            try:
+                import ctypes
+                ctypes.windll.user32.SetProcessDPIAware()
+            except Exception:
+                pass
+
+
+def dpi_scale(widget) -> float:
+    try:
+        return max(1.0, widget.winfo_fpixels("1i") / 96.0)
+    except Exception:
+        return 1.0
+
+
+# ── Color accents ─────────────────────────────────────────────────────────────
+# Each feature area has its own accent color scheme: (light_mode, dark_mode)
+
+ACCENT_BLUE = {
+    "fg":    ("#3B82F6", "#2563EB"),
+    "hover": ("#2563EB", "#1D4ED8"),
+}
+
+ACCENT_PURPLE = {
+    "fg":       ("#EDE9FE", "#3B1F6E"),
+    "text":     ("#5B21B6", "#C4B5FD"),
+    "hover":    ("#DDD6FE", "#4C2889"),
+    "preview":  ("#7C3AED", "#A78BFA"),
+}
+
+ACCENT_GREEN = {
+    "fg":    ("#10B981", "#059669"),
+    "hover": ("#059669", "#047857"),
+}
+
+ACCENT_AMBER = {
+    "fg":    ("#F59E0B", "#D97706"),
+    "hover": ("#D97706", "#B45309"),
+}
+
+# Neutral button style
+BTN_NEUTRAL = {
+    "fg_color":    ("gray80", "gray25"),
+    "text_color":  ("gray10", "gray90"),
+    "hover_color": ("gray70", "gray35"),
+}
+
+BTN_SIDE = {
+    "fg_color":    ("gray82", "gray22"),
+    "text_color":  ("gray10", "gray90"),
+    "hover_color": ("gray72", "gray32"),
+}