Clean up LSP diagnostics across backend and frontend

Backend (nvcurve/):
- hal/fans.py, hal/limits.py, hal/gpu.py: replace conditional pynvml
  imports with the established 'pynvml: Any = _pynvml_import' pattern
  (fixes ~50 'possibly unbound' errors); type the result dicts; guard
  query_interface() results; explicit uuid/pci-bus parsing (int, hex
  convention documented); modernize Optional[T] -> T | None
- cli.py: fix 'curve_state' possibly-unbound and snap_path None handling
  in cmd_setup; wrap unchecked int()/open()/makedirs() calls in
  try/except with clean CLI errors; add module logger for silent
  except-pass blocks; raise ... from exc; fix unused loop vars and
  set-comprehension
- hal/snapshot.py: filepath: str | None; wrap all file ops; sorted
  imports; remove unused CT_POINTS import
- daemon.py: extract 0o666 to _SOCKET_MODE constant (intentional for
  /run sockets) with nosemgrep
- server.py: nosemgrep for Python 3.7-compat false positive (project
  requires >= 3.12); log previously-swallowed exception
- profiles/native.py, profiles/apply.py: wrap file ops and int(k)
  profile-key parsing; sorted imports; modernize typing

Frontend (frontend/src):
- Add .js extensions to all relative imports (standard TS-ESM; Vite
  resolves .js -> .ts)
- React.FormEvent (deprecated in React 19 types) -> React.SubmitEvent
- catch (e: any) -> catch (e: unknown) + instanceof Error narrowing
- React-hooks: move ref writes from render into effects; convert
  viewport reset to render-phase state adjustment; split
  selectPoint(index, multi) into selectPoint + togglePoint (no flag
  argument); remove non-null assertion
- Static inline styles -> Tailwind classes (dynamic positioning/cursor
  styles kept)
- Remove non-standard 'container' option from scrollIntoView (browsers
  ignore unknown options) which had orphaned a @ts-expect-error
- Object.fromEntries for Map -> Record conversion

Tooling:
- .gitignore: ignore .codegraph/ local tool data

Verified: tsc --noEmit, vite production build, python imports, and
full LSP scan (0 errors/warnings in both projects).

frontend/src/components/Monitor/PerformanceMonitor.tsx

@@ -1,6 +1,6 @@
-import { GaugeCard } from './GaugeCard';
-import { fmt } from '../../utils/units';
-import type { MonitoringSample } from '../../types';
+import { GaugeCard } from "./GaugeCard.js";
+import { fmt } from "../../utils/units.js";
+import type { MonitoringSample } from "../../types.js";
 
 interface Props {
   monitor: MonitoringSample | null;
@@ -17,35 +17,38 @@ function pluck<K extends keyof MonitoringSample>(
 export function PerformanceMonitor({ monitor, history }: Props) {
   const memUsed = monitor?.mem_used_mib ?? null;
   const memTotal = monitor?.mem_total_mib ?? null;
-  const memLabel = memUsed != null && memTotal != null
-    ? `${memUsed.toFixed(0)} / ${memTotal.toFixed(0)} MiB`
-    : '—';
+  const memLabel =
+    memUsed != null && memTotal != null
+      ? `${memUsed.toFixed(0)} / ${memTotal.toFixed(0)} MiB`
+      : "—";
 
   return (
     <div className="flex flex-col gap-2 w-full h-full">
       <div className="bg-zinc-900 rounded-lg p-3 flex flex-col gap-2 h-full">
         <div className="flex items-center justify-between pb-2 border-b border-zinc-800">
-          <span className="text-xs text-zinc-500 uppercase tracking-wider font-semibold">Live Monitor</span>
+          <span className="text-xs text-zinc-500 uppercase tracking-wider font-semibold">
+            Live Monitor
+          </span>
         </div>
         <div className="flex flex-col gap-2 mt-1">
           <GaugeCard
             label="Mem Clock"
             value={fmt.mhz(monitor?.mem_clock_mhz)}
-            history={pluck(history, 'mem_clock_mhz')}
+            history={pluck(history, "mem_clock_mhz")}
             color="#67e8f9"
             max={20000}
           />
           <GaugeCard
             label="Power Draw"
             value={fmt.watts(monitor?.power_w)}
-            history={pluck(history, 'power_w')}
+            history={pluck(history, "power_w")}
             color="#f472b6"
             max={600}
           />
           <GaugeCard
             label="VRAM Used"
             value={memLabel}
-            history={pluck(history, 'mem_used_mib')}
+            history={pluck(history, "mem_used_mib")}
             color="#a78bfa"
             max={memTotal ?? 32768}
           />