feat(host,web): host log ring + GET /api/v1/logs + console Logs page

Remote debugging without shell access: a tracing layer tees every
event at DEBUG-and-up — independent of the RUST_LOG filter gating
stderr/host.log, so console-side debugging never needs a restart —
into a bounded in-memory ring (log_capture.rs, 4096 newest entries,
OnceLock singleton like config()), installed at both init sites
(stderr path in main, the Windows service file path). The mgmt API
serves it cursor-paged at GET /api/v1/logs?after=&limit= — bearer-only
and deliberately NOT on the mTLS cert allowlist (log lines can name
client identities and host paths). The web console grows a Logs page
(follow/pause · min-level filter · text search · eviction-gap badge);
polling self-paces: a non-empty page advances the after-cursor (new
query key → immediate refetch, drains backlogs), an empty page idles
at the 2s interval. OpenAPI regenerated; ring pagination/eviction,
layer wiring, and the authed route are unit-tested; Storybook story
included.

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

web/src/components/app-shell.tsx

@@ -4,6 +4,7 @@ import {
 	GaugeCircle,
 	KeyRound,
 	LibraryBig,
+	ScrollText,
 	Server,
 	Settings,
 } from "lucide-react";
@@ -22,6 +23,7 @@ const NAV = [
 	{ to: "/host", icon: Server, label: () => m.nav_host() },
 	{ to: "/library", icon: LibraryBig, label: () => m.nav_library() },
 	{ to: "/stats", icon: GaugeCircle, label: () => m.nav_stats() },
+	{ to: "/logs", icon: ScrollText, label: () => m.nav_logs() },
 	{ to: "/pairing", icon: KeyRound, label: () => m.nav_pairing() },
 	{ to: "/settings", icon: Settings, label: () => m.nav_settings() },
 ] as const;