Fix pre-existing player issues: edit upload paths, playlist sync, DPI, console

src/edit_popup.py: pass and reproduce the server-side edited-media layout
('edited_media/<media_id>/') when saving an edit, falling back to the flat
folder when no media id is available, so uploads land where the server expects.

src/get_playlists_v2.py: preserve every server field (audio, muted, description,
id, position, ...) when rewriting playlist items, instead of rebuilding fixed
dicts that silently dropped them. Web-link items keep their original http(s) url
and are never downloaded.

windows/pyi_runtime_hook.py: declare per-monitor DPI awareness before SDL/Kivy
initialise, so on a scaled display the window is not virtualised to a smaller
resolution (which left a black strip and mis-scaled media).

windows/build_win.bat: optional code signing step for PCs with Smart App Control
enabled, driven by KIWY_SIGN_PFX / KIWY_SIGN_PFX_PASSWORD or a local
kiwy_signing.pfx.

windows/build.spec, windows/README_WINDOWS_BUILD.md, windows/development-track.md:
build notes and manifest updates.

windows/development-track.md

@@ -6,7 +6,7 @@
 
 ---
 
-## 📅 Current Session — 2026-07-31
+## 📅 Current Session — 2026-08-07
 
 | Field | Value |
 |-------|-------|
@@ -14,9 +14,37 @@
 | **Python** | 3.12.9 — `windows\venv\` (250 MB, all deps installed) |
 | **Kivy** | 2.3.1 |
 | **PyInstaller** | 6.21.0 |
-| **Last .exe build** | 2026-07-26 16:53 — `windows\dist\KiwySignagePlayer\KiwySignagePlayer.exe` (96 MB) |
+| **Last .exe build** | 2026-08-07 08:23 — `windows\dist\KiwySignagePlayer\KiwySignagePlayer.exe` (98.8 MB) |
 | **Build command** | `.\venv\Scripts\python.exe -m PyInstaller build.spec --clean --noconfirm` |
 
+### Overnight soak test findings (2026-08-07 morning)
+
+- **Symptom:** player froze on the last video widget (never advanced past
+  `video_loaded`); heartbeat stopped; 7 leaked `msedge.exe` processes left
+  running in the background.
+- **Root cause (two compounding bugs in `run_win.py`):**
+  1. **Leaked browser + instant-exit handoff.** A previously leaked Chrome/Edge
+     process held the `.kiosk-profile` lock. The next weblink launch handed
+     the URL to that leaked instance and **exited in ~2s** (`07:04:57` launch →
+     `07:04:59 next_media_called`). The watchdog advanced instantly, so the
+     weblink never showed AND the leaked browser window was never killed →
+     `msedge.exe` processes accumulated overnight.
+  2. **Main-thread freeze.** The focus keeper ran heavy Win32 work
+     (`EnumWindows` + `AttachThreadInput` + `SetForegroundWindow` + `SendInput`)
+     synchronously on the Kivy thread every second. With leaked Edge windows
+     fighting back, this wedged the event loop → video never advanced, heartbeat
+     stopped (`08-07 07:09`).
+- **Fix (in `run_win.py`, rebuilt 08:23):**
+  1. New `_windows_kill_browsers_on_profile()` — scans `chrome/msedge/chromium`
+     command lines (WMIC, PowerShell fallback), taskkills any browser holding
+     the `.kiosk-profile` lock. Called **before every weblink launch**.
+  2. Watchdog now has `MIN_ALIVE_BEFORE_EARLY_ADVANCE = 8s` — an instant
+     (~2s) handoff exit no longer advances/skips the weblink.
+  3. `_bring_kivy_to_front(async_ok=True)` runs the heavy Win32 bring-to-front
+     on a **background worker thread** guarded by a lock, so the Kivy main
+     thread is never blocked. Synchronous `async_ok=False` still available for
+     explicit transitions.
+
 ### 📋 Cross-platform audit — Linux commands → Windows handling
 
 Every Linux-only command in `src/` was cross-referenced against the patches