chore: consolidate parallel-session WIP (HOLD — do not push)

Local snapshot of intermingled in-flight work, committed to unblock the encode
refactor (a clean ffmpeg_win.rs for the vbv-dedup follow-on). These hunks span
the same files and can't be cleanly split here; the commit bundles three
distinct workstreams that each belong in their own PR:

  - logging rework (~43 files: level re-tiering, structured fields, `?e`,
    hot-path flood latches)
  - conflicting-host detection (detect.rs + detect/{linux,windows}.rs + wiring
    in main.rs/mgmt.rs/Cargo.toml/docs/packaging)
  - standby-sink DWM-stall attribution (windows/display_events.rs + capture/
    vdisplay wiring)

NOT verified as a combination. NOT to be pushed until the refactor is done and
these are re-verified and reorganized into their proper per-workstream PRs.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

crates/punktfunk-host/Cargo.toml

@@ -217,6 +217,9 @@ windows = { version = "0.62", features = [
     # (src/windows/crash.rs); Kernel gates the CONTEXT type EXCEPTION_POINTERS embeds.
     "Win32_System_Diagnostics_Debug",
     "Win32_System_Kernel",
+    # CreateToolhelp32Snapshot/Process32*W — the conflicting-streaming-host process scan
+    # (src/detect/windows.rs): is Sunshine/Apollo/... running alongside us?
+    "Win32_System_Diagnostics_ToolHelp",
 ] }
 # The SCM plumbing for the `service` subcommand (define_windows_service! / dispatcher / control
 # handler / ServiceManager install). Wraps the Win32 service API; the supervision loop itself uses