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/CurveEditor/CurveToolbar.tsx

@@ -1,7 +1,7 @@
-import { useState, useMemo, useEffect } from 'react';
-import { ZoomIn, RotateCcw, Minus } from 'lucide-react';
-import { useCurveStore } from '../../store/curveStore';
-import type { VFPoint } from '../../types';
+import { useState, useMemo } from "react";
+import { ZoomIn, RotateCcw, Minus } from "lucide-react";
+import { useCurveStore } from "../../store/curveStore.js";
+import type { VFPoint } from "../../types.js";
 
 interface Props {
   /** All curve points — used by global offset slider */
@@ -18,23 +18,44 @@ interface Props {
   onZoomChange: (factor: number) => void;
 }
 
-export function CurveToolbar({ activePts, onResetZoom, isZoomed, readOnly, zoomFactor, onZoomChange }: Props) {
-  const { pendingDeltas, selectedPoints, anchorPoint, curve, stageRangeEdit, flattenToAnchor } = useCurveStore();
+export function CurveToolbar({
+  activePts,
+  onResetZoom,
+  isZoomed,
+  readOnly,
+  zoomFactor,
+  onZoomChange,
+}: Props) {
+  const {
+    pendingDeltas,
+    selectedPoints,
+    anchorPoint,
+    curve,
+    stageRangeEdit,
+    flattenToAnchor,
+  } = useCurveStore();
 
   const [offsetMhz, setOffsetMhz] = useState(0);
 
   const uniformDeltaMhz = useMemo(() => {
     if (activePts.length === 0) return 0;
-    const firstD = pendingDeltas.get(activePts[0].index) ?? activePts[0].delta_khz;
-    const uniform = activePts.every((p) => (pendingDeltas.get(p.index) ?? p.delta_khz) === firstD);
+    const firstD =
+      pendingDeltas.get(activePts[0].index) ?? activePts[0].delta_khz;
+    const uniform = activePts.every(
+      (p) => (pendingDeltas.get(p.index) ?? p.delta_khz) === firstD,
+    );
     return uniform ? firstD / 1000 : null;
   }, [activePts, pendingDeltas]);
 
-  useEffect(() => {
-    if (uniformDeltaMhz !== null) {
-      setOffsetMhz(uniformDeltaMhz);
-    }
-  }, [uniformDeltaMhz]);
+  // Sync the slider to the uniform delta when it changes (adjust state during
+  // render instead of an effect; undefined sentinel so the first render syncs).
+  const [lastUniformDelta, setLastUniformDelta] = useState<
+    number | null | undefined
+  >();
+  if (uniformDeltaMhz !== null && lastUniformDelta !== uniformDeltaMhz) {
+    setLastUniformDelta(uniformDeltaMhz);
+    setOffsetMhz(uniformDeltaMhz);
+  }
 
   function handleOffsetChange(mhz: number) {
     setOffsetMhz(mhz);
@@ -44,7 +65,10 @@ export function CurveToolbar({ activePts, onResetZoom, isZoomed, readOnly, zoomF
   return (
     <div className="flex flex-wrap items-center gap-2 px-1 pb-2">
       {/* Zoom control */}
-      <div className="flex items-center gap-1.5 px-2 py-1 rounded bg-zinc-800/60 border border-zinc-700/40" title="Zoom x-axis (Alt+scroll also works)">
+      <div
+        className="flex items-center gap-1.5 px-2 py-1 rounded bg-zinc-800/60 border border-zinc-700/40"
+        title="Zoom x-axis (Alt+scroll also works)"
+      >
         <ZoomIn size={11} className="text-zinc-500 shrink-0" />
         <input
           type="range"
@@ -55,7 +79,9 @@ export function CurveToolbar({ activePts, onResetZoom, isZoomed, readOnly, zoomF
           onChange={(e) => onZoomChange(Number(e.target.value))}
           className="w-20 h-1 cursor-pointer accent-cyan-400"
         />
-        <span className={`text-xs font-mono w-8 tabular-nums ${isZoomed ? 'text-cyan-400' : 'text-zinc-600'}`}>
+        <span
+          className={`text-xs font-mono w-8 tabular-nums ${isZoomed ? "text-cyan-400" : "text-zinc-600"}`}
+        >
           {zoomFactor.toFixed(1)}×
         </span>
         {isZoomed && (
@@ -75,7 +101,9 @@ export function CurveToolbar({ activePts, onResetZoom, isZoomed, readOnly, zoomF
       {/* Global offset slider — GPU only */}
       {!readOnly && uniformDeltaMhz !== null && (
         <div className="flex items-center gap-1.5 min-w-[260px]">
-          <span className="text-zinc-500 text-xs whitespace-nowrap">Global Offset</span>
+          <span className="text-zinc-500 text-xs whitespace-nowrap">
+            Global Offset
+          </span>
           <input
             type="range"
             min={-1000}
@@ -84,46 +112,63 @@ export function CurveToolbar({ activePts, onResetZoom, isZoomed, readOnly, zoomF
             value={offsetMhz}
             onChange={(e) => handleOffsetChange(Number(e.target.value))}
             className="w-32 accent-cyan-400"
-            title={`${offsetMhz > 0 ? '+' : ''}${offsetMhz} MHz`}
+            title={`${offsetMhz > 0 ? "+" : ""}${offsetMhz} MHz`}
           />
           <span
             className={[
-              'text-xs font-mono w-16',
-              offsetMhz > 0 ? 'text-cyan-400' : offsetMhz < 0 ? 'text-orange-400' : 'text-zinc-500',
-            ].join(' ')}
+              "text-xs font-mono w-16",
+              offsetMhz > 0
+                ? "text-cyan-400"
+                : offsetMhz < 0
+                  ? "text-orange-400"
+                  : "text-zinc-500",
+            ].join(" ")}
           >
-            {offsetMhz > 0 ? '+' : ''}{offsetMhz} MHz
+            {offsetMhz > 0 ? "+" : ""}
+            {offsetMhz} MHz
           </span>
         </div>
       )}
 
       {/* Flatten — visible when 2+ points are selected */}
-      {!readOnly && selectedPoints.size >= 2 && (() => {
-        const anchor = anchorPoint !== null && selectedPoints.has(anchorPoint)
-          ? anchorPoint
-          : Math.min(...selectedPoints);
-        const anchorDelta =
-          pendingDeltas.get(anchor) ??
-          curve?.points.find(p => p.index === anchor)?.delta_khz ??
-          0;
-        const label = `·${anchor}  ${anchorDelta >= 0 ? '+' : ''}${anchorDelta / 1000} MHz`;
-        return (
-          <button
-            onClick={flattenToAnchor}
-            className="flex items-center gap-1.5 px-2 py-1 rounded text-xs font-medium text-amber-400 hover:text-amber-300 hover:bg-zinc-800 border border-zinc-700/40 transition"
-            title={`Flatten all selected points to anchor point ${anchor} (${anchorDelta >= 0 ? '+' : ''}${anchorDelta / 1000} MHz)`}
-          >
-            <Minus size={11} />
-            Flatten to {label}
-          </button>
-        );
-      })()}
+      {!readOnly &&
+        selectedPoints.size >= 2 &&
+        (() => {
+          const anchor =
+            anchorPoint !== null && selectedPoints.has(anchorPoint)
+              ? anchorPoint
+              : Math.min(...selectedPoints);
+          const anchorDelta =
+            pendingDeltas.get(anchor) ??
+            curve?.points.find((p) => p.index === anchor)?.delta_khz ??
+            0;
+          const label = `·${anchor}  ${anchorDelta >= 0 ? "+" : ""}${anchorDelta / 1000} MHz`;
+          return (
+            <button
+              onClick={flattenToAnchor}
+              className="flex items-center gap-1.5 px-2 py-1 rounded text-xs font-medium text-amber-400 hover:text-amber-300 hover:bg-zinc-800 border border-zinc-700/40 transition"
+              title={`Flatten all selected points to anchor point ${anchor} (${anchorDelta >= 0 ? "+" : ""}${anchorDelta / 1000} MHz)`}
+            >
+              <Minus size={11} />
+              Flatten to {label}
+            </button>
+          );
+        })()}
 
       {/* Legend — right-aligned */}
       <div className="flex items-center gap-3 text-xs text-zinc-500 ml-auto">
-        <span className="flex items-center gap-1"><span className="inline-block w-3 h-0.5 bg-emerald-400 rounded" /> effective</span>
-        <span className="flex items-center gap-1"><span className="inline-block w-3 h-px border-t-2 border-dashed border-cyan-400" /> pending</span>
-        <span className="flex items-center gap-1"><span className="inline-block w-2 h-2 rounded-full bg-yellow-400" /> current</span>
+        <span className="flex items-center gap-1">
+          <span className="inline-block w-3 h-0.5 bg-emerald-400 rounded" />{" "}
+          effective
+        </span>
+        <span className="flex items-center gap-1">
+          <span className="inline-block w-3 h-px border-t-2 border-dashed border-cyan-400" />{" "}
+          pending
+        </span>
+        <span className="flex items-center gap-1">
+          <span className="inline-block w-2 h-2 rounded-full bg-yellow-400" />{" "}
+          current
+        </span>
       </div>
     </div>
   );

frontend/src/components/CurveEditor/CurveTooltip.tsx

@@ -1,5 +1,5 @@
-import { fmt } from '../../utils/units';
-import type { VFPoint } from '../../types';
+import { fmt } from '../../utils/units.js';
+import type { VFPoint } from '../../types.js';
 
 interface Props {
   point: VFPoint;
@@ -21,15 +21,7 @@ export function CurveTooltip({ point, pendingDeltaKhz, isClamped }: Props) {
 
   return (
     <div
-      style={{
-        position: 'absolute',
-        right: 16,
-        bottom: 16,
-        pointerEvents: 'none',
-        zIndex: 50,
-        width: 172,
-      }}
-      className="bg-zinc-800 border border-zinc-700 rounded-md p-2 text-xs shadow-xl"
+      className="absolute right-4 bottom-4 pointer-events-none z-50 w-[172px] bg-zinc-800 border border-zinc-700 rounded-md p-2 text-xs shadow-xl"
     >
       <div className="text-zinc-400 mb-1">Point {point.index}</div>
       <div className="text-zinc-200">