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/hooks/useCurve.ts

@@ -1,12 +1,14 @@
-import { useEffect, useRef, useState } from 'react';
-import { api } from '../api/client';
-import { createWsConnection } from '../api/websocket';
-import { useCurveStore } from '../store/curveStore';
-import type { CurveState } from '../types';
+import { useEffect, useRef, useState } from "react";
+import { api } from "../api/client.js";
+import { createWsConnection } from "../api/websocket.js";
+import { useCurveStore } from "../store/curveStore.js";
+import type { CurveState } from "../types.js";
 
 export function useCurve() {
   const { curve, setCurve, selectedGpuIndex } = useCurveStore();
-  const [wsStatus, setWsStatus] = useState<'connecting' | 'connected' | 'disconnected'>('connecting');
+  const [wsStatus, setWsStatus] = useState<
+    "connecting" | "connected" | "disconnected"
+  >("connecting");
   const wsRef = useRef<ReturnType<typeof createWsConnection> | null>(null);
 
   useEffect(() => {
@@ -15,7 +17,7 @@ export function useCurve() {
 
     // Subscribe to /ws/curve for push updates after writes
     wsRef.current = createWsConnection<CurveState>(
-      '/ws/curve',
+      "/ws/curve",
       (data) => setCurve(data),
       setWsStatus,
       selectedGpuIndex,