refactor(host/W6.1): extract the config() global into the pf-host-config leaf crate

Third de-coupling for the host crate carve (plan §W6.1 leaf). HostConfig + the config()
OnceLock (config.rs, pure std, zero deps) move to a new pf-host-config leaf so every
subsystem crate (pf-encode/pf-capture/pf-vdisplay/pf-gpu) can read process config WITHOUT
depending on the orchestrator. 34 crate::config::config() call sites across 19 files
repoint to pf_host_config::config(). thread_qos stays in the host for now (it calls
session_tuning::on_hot_thread — its own leaf-ification rides the encode carve).

Granular-crate decision (supersedes the plan's single pf-media): split capture/encode/
vdisplay into separate crates rather than one broad crate — the capture↔encode cycle is
broken by a shared frame-types leaf, and vdisplay→encode (can_open_another_session) is a
legal one-way edge since encode never references vdisplay.

Verified: Linux (home-worker-5) clippy -p pf-host-config -p punktfunk-host --all-targets
-D warnings; Windows (192.168.1.158) clippy --features nvenc,amf-qsv --all-targets green.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

crates/punktfunk-host/src/gamestream/mod.rs

@@ -64,7 +64,7 @@ pub const SERVER_CODEC_MODE_SUPPORT: u32 = SCM_H264 | SCM_HEVC | SCM_AV1_MAIN8;
 /// whenever the desktop is HDR, and a client HDR request makes the GameStream video path proactively
 /// enable advanced color on the per-session virtual display so PQ flows even from an SDR desktop.
 pub fn host_hdr_capable() -> bool {
-    cfg!(target_os = "windows") && crate::config::config().ten_bit
+    cfg!(target_os = "windows") && pf_host_config::config().ten_bit
 }
 
 /// Stable host identity + advertised capabilities, shared across control-plane handlers.

crates/punktfunk-host/src/gamestream/stream.rs

@@ -162,7 +162,7 @@ fn run(
     // request and capture it (no scaling). Self-contained — deliberately NOT pooled in
     // `video_cap`, since a reconnect at a different resolution needs a freshly-sized output; the
     // output is released when this capturer drops at stream end (RAII via its keepalive).
-    if crate::config::config().video_source.as_deref() == Some("virtual") {
+    if pf_host_config::config().video_source.as_deref() == Some("virtual") {
         // Per-app prep steps (RFC §6): the entry's own `prep` plus a custom library title's,
         // run synchronously BEFORE the virtual output opens or anything launches (an HDR
         // toggle / sink switch must land first — and gamescope's nested launch happens inside
@@ -249,7 +249,7 @@ fn run(
             tracing::info!("video source: reusing capturer");
             c
         }
-        None if crate::config::config().video_source.as_deref() == Some("portal") => {
+        None if pf_host_config::config().video_source.as_deref() == Some("portal") => {
             tracing::info!("video source: portal desktop capture");
             capture::open_portal_monitor().context("open portal capturer")?
         }
@@ -676,7 +676,7 @@ fn stream_body(
 
     // Per-stage timing (PUNKTFUNK_PERF=1): max µs/stage per second + unique vs re-encoded frames,
     // to pinpoint stalls. `unique` counts genuinely-new captured frames (vs re-encoded holds).
-    let perf = crate::config::config().perf;
+    let perf = pf_host_config::config().perf;
     let (mut mx_cap, mut mx_enc, mut mx_pkt, mut mx_send, mut uniq) =
         (0u128, 0u128, 0u128, 0u128, 0u32);
     // Web-console stats accumulation (active when `perf` OR a capture is armed): per-stage vectors