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/Fans/FanCurveEditor.tsx

@@ -1,10 +1,10 @@
 import { useState, useEffect, useRef, useCallback } from "react";
 import { Check, X, RotateCcw, Plus } from "lucide-react";
-import { api } from "../../api/client";
-import { useCurveStore } from "../../store/curveStore";
-import type { FanPoint, FanState } from "../../types";
+import { api } from "../../api/client.js";
+import { useCurveStore } from "../../store/curveStore.js";
+import type { FanPoint, FanState } from "../../types.js";
 import { toast } from "sonner";
-import { ConfirmDialog } from "../common/ConfirmDialog";
+import { ConfirmDialog } from "../common/ConfirmDialog.js";
 
 function defaultCurve(): FanPoint[] {
   return [
@@ -71,7 +71,10 @@ export function FanCurveEditor({ onChanged }: { onChanged?: () => void }) {
     }
   }
 
+  // Data fetch on GPU change — setState calls happen after the await, not
+  // synchronously in the effect body (rule false-positive on async fetch).
   useEffect(() => {
+    // eslint-disable-next-line react-hooks/set-state-in-effect
     fetchFans();
   }, [selectedGpuIndex]);
 
@@ -92,8 +95,8 @@ export function FanCurveEditor({ onChanged }: { onChanged?: () => void }) {
       await fetchFans();
       onChanged?.();
       toast.success("Fan curve applied");
-    } catch (e: any) {
-      setError(e.message ?? String(e));
+    } catch (e: unknown) {
+      setError(e instanceof Error ? e.message : String(e));
       setConfirmApply(false);
     } finally {
       setBusy(false);
@@ -110,8 +113,8 @@ export function FanCurveEditor({ onChanged }: { onChanged?: () => void }) {
       await fetchFans();
       onChanged?.();
       toast.success("Fan control reset to automatic");
-    } catch (e: any) {
-      setError(e.message ?? String(e));
+    } catch (e: unknown) {
+      setError(e instanceof Error ? e.message : String(e));
       setConfirmReset(false);
     } finally {
       setBusy(false);
@@ -294,8 +297,7 @@ export function FanCurveEditor({ onChanged }: { onChanged?: () => void }) {
             ref={svgRef}
             width="100%"
             viewBox={`0 0 ${CHART_W} ${CHART_H}`}
-            className="max-w-full cursor-crosshair select-none"
-            style={{ touchAction: "none" }}
+            className="max-w-full cursor-crosshair select-none touch-none"
             onClick={handleCanvasClick}
             onPointerMove={handlePointerMove}
           >
@@ -410,8 +412,7 @@ export function FanCurveEditor({ onChanged }: { onChanged?: () => void }) {
                   fill={hasPending ? "#22d3ee" : "#fb923c"}
                   stroke="#09090b"
                   strokeWidth="2"
-                  className="cursor-grab active:cursor-grabbing"
-                  style={{ touchAction: "none" }}
+                  className="cursor-grab active:cursor-grabbing touch-none"
                   onPointerDown={(e) => {
                     e.stopPropagation();
                     handlePointerDown(i);