fix: fan settings persistence, profile indicator, and point removal

Address three fan-settings issues:

1. Profile view: show a fan icon next to a profile's name when it has a
   saved fan curve, so it's clear which profiles carry custom fans.

2. Fan curve persistence: the active fan curve was in-memory only and lost
   on every server restart. It is now persisted per-GPU in
   /etc/nvcurve/config.json (fan_curves) and re-applied at server startup,
   so an applied curve survives restarts. All fan-curve state changes route
   through _activate_fan_curve/_deactivate_fan_curve helpers that keep the
   persisted state in sync (apply, reset, and profile apply).

3. Point removal: the fan-curve remove button was nearly invisible. The
   chart remove control is now always faintly visible with an X glyph, the
   table remove button is larger with a tooltip, and a hint line explains
   how to add/remove points.

Also includes a formatting pass over the two edited frontend files.

nvcurve/cli.py

@@ -2092,6 +2092,9 @@ def main():
             elif "auto_load_profile" in data:
                 # Migrate old single-string format — GPU 0, no UUID known at this point
                 cfg.auto_load_profiles = {"idx:0": data["auto_load_profile"]}
+            if "fan_curves" in data:
+                # Per-GPU active fan curves, restored on server startup.
+                cfg.fan_curves = dict(data["fan_curves"])
     except Exception:
         pass
 

nvcurve/config.py

@@ -30,6 +30,13 @@ class Config:
     # Value = profile name (str).
     auto_load_profiles: dict[str, str] = field(default_factory=dict)
 
+    # Per-GPU active fan curves: restored automatically on server startup so a
+    # curve applied via the UI survives server restarts (fan control itself is
+    # volatile — the driver reverts to automatic mode on reboot).
+    # Key = stable GPU identifier (same as auto_load_profiles).
+    # Value = list of {"temp_c": int, "fan_pct": int} sorted by temp_c.
+    fan_curves: dict[str, list] = field(default_factory=dict)
+
 
 # Module-level default config instance.
 default_config = Config()

nvcurve/server.py

@@ -237,6 +237,58 @@ async def _fan_poller(gpu_index: int) -> None:
         await asyncio.sleep(2.0)
 
 
+async def _activate_fan_curve(gpu_index: int, curve: list) -> None:
+    """Set the active fan curve, (re)start the poller, and persist it.
+
+    Persistence (config.json) is what makes the curve survive server restarts:
+    fan control is volatile, so the driver reverts to automatic mode on reboot
+    and the saved curve is re-applied at the next server start.
+    """
+    g_state = _get_gpu_state(gpu_index)
+
+    # Stop existing poller if running
+    if g_state.get("fan_poller_task"):
+        g_state["fan_poller_task"].cancel()
+        with suppress(asyncio.CancelledError):
+            await g_state["fan_poller_task"]
+
+    g_state["fan_curve"] = curve
+    g_state["fan_curve_active"] = True
+    g_state["fan_poller_task"] = asyncio.create_task(_fan_poller(gpu_index))
+
+    cfg: Config = _state["config"]
+    cfg.fan_curves[_gpu_stable_key(gpu_index)] = curve
+    _persist_fan_curves(cfg.fan_curves)
+
+
+async def _deactivate_fan_curve(gpu_index: int, reset_hardware: bool = True) -> None:
+    """Clear the active fan curve, stop the poller, and clear its persistence.
+
+    When reset_hardware is True the GPU is returned to automatic fan control.
+    """
+    g_state = _get_gpu_state(gpu_index)
+
+    if g_state.get("fan_poller_task"):
+        g_state["fan_poller_task"].cancel()
+        with suppress(asyncio.CancelledError):
+            await g_state["fan_poller_task"]
+        g_state["fan_poller_task"] = None
+
+    g_state["fan_curve"] = None
+    g_state["fan_curve_active"] = False
+
+    if reset_hardware:
+        ok, msg = await _run(reset_fan, gpu_index)
+        if not ok:
+            log.warning("Fan reset warning: %s", msg)
+
+    cfg: Config = _state["config"]
+    key = _gpu_stable_key(gpu_index)
+    if key in cfg.fan_curves:
+        del cfg.fan_curves[key]
+        _persist_fan_curves(cfg.fan_curves)
+
+
 # ── Lifespan ──────────────────────────────────────────────────────────────────
 
 
@@ -326,6 +378,35 @@ async def lifespan(app: FastAPI):
                 )
     # ──────────────────────────────────────────────────────────────────────────
 
+    # ── Restore persisted fan curves ──────────────────────────────────────────
+    # Fan control is volatile: the driver reverts to automatic mode on reboot,
+    # so a curve applied via the UI is persisted in config.json and re-applied
+    # here at startup. Runs after the auto-load profile path so the user's
+    # explicit fan curve setting takes precedence.
+    for gpu_index, g_state in _state["gpus"].items():
+        if g_state["gpu"] is None:
+            continue
+        if g_state.get("fan_curve_active"):
+            continue  # already activated by the auto-load profile path
+        key = _gpu_stable_key(gpu_index)
+        curve = cfg.fan_curves.get(key)
+        if not curve:
+            continue
+        ok, msg = validate_curve(curve)
+        if not ok:
+            log.warning("Skipping persisted fan curve for GPU %d: %s", gpu_index, msg)
+            continue
+        log.info("Restoring persisted fan curve on GPU %d (%s)", gpu_index, key)
+        try:
+            await _activate_fan_curve(gpu_index, curve)
+        except Exception as exc:
+            log.warning(
+                "Failed to restore persisted fan curve on GPU %d: %s",
+                gpu_index,
+                exc,
+            )
+    # ──────────────────────────────────────────────────────────────────────────
+
     yield  # server is running
 
     for task in poller_tasks:
@@ -745,6 +826,11 @@ def _persist_auto_load_profiles(profiles: dict[str, str]) -> None:
     _persist_config_field("auto_load_profiles", profiles if profiles else None)
 
 
+def _persist_fan_curves(fan_curves: dict) -> None:
+    """Persist the per-GPU active fan curves dict to config.json."""
+    _persist_config_field("fan_curves", fan_curves if fan_curves else None)
+
+
 @app.get("/api/profiles")
 async def api_profiles(gpu_index: int = 0):
     """List saved native profiles, the active profile name, and the auto-load profile name."""
@@ -931,31 +1017,16 @@ async def _apply_profile(name: str, gpu_index: int = 0) -> list[str]:
 
         await _update_offsets_and_broadcast(gpu_index)
 
-    # Apply fan curve if present in profile
+    # Apply fan curve if present in profile (persists it so it survives restarts);
+    # otherwise deactivate any active fan curve (and clear its persistence).
     if profile.fan_curve:
         ok, msg = validate_curve(profile.fan_curve)
         if not ok:
             errs.append(f"Fan curve: {msg}")
         else:
-            # Stop existing fan poller if running
-            if g_state.get("fan_poller_task"):
-                g_state["fan_poller_task"].cancel()
-                with suppress(asyncio.CancelledError):
-                    await g_state["fan_poller_task"]
-
-            g_state["fan_curve"] = profile.fan_curve
-            g_state["fan_curve_active"] = True
-            g_state["fan_poller_task"] = asyncio.create_task(_fan_poller(gpu_index))
+            await _activate_fan_curve(gpu_index, profile.fan_curve)
     elif g_state.get("fan_curve_active"):
-        # Profile has no fan curve, deactivate any active fan curve
-        if g_state.get("fan_poller_task"):
-            g_state["fan_poller_task"].cancel()
-            with suppress(asyncio.CancelledError):
-                await g_state["fan_poller_task"]
-            g_state["fan_poller_task"] = None
-        g_state["fan_curve"] = None
-        g_state["fan_curve_active"] = False
-        await _run(reset_fan, gpu_index)
+        await _deactivate_fan_curve(gpu_index, reset_hardware=True)
 
     if not errs:
         g_state["active_profile"] = name
@@ -1196,15 +1267,8 @@ async def api_fans_update(req: FanCurveRequest, gpu_index: int = 0):
                     status_code=500, detail=f"Fan control not available: {fan_msg}"
                 )
 
-    # Stop existing poller if running
-    if g_state.get("fan_poller_task"):
-        g_state["fan_poller_task"].cancel()
-        with suppress(asyncio.CancelledError):
-            await g_state["fan_poller_task"]
-
-    g_state["fan_curve"] = curve_data
-    g_state["fan_curve_active"] = True
-    g_state["fan_poller_task"] = asyncio.create_task(_fan_poller(gpu_index))
+    # Activate the curve (starts the poller) and persist it so it survives restarts.
+    await _activate_fan_curve(gpu_index, curve_data)
 
     return {"ok": True}
 
@@ -1212,21 +1276,11 @@ async def api_fans_update(req: FanCurveRequest, gpu_index: int = 0):
 @app.post("/api/fans/reset")
 async def api_fans_reset(gpu_index: int = 0):
     """Deactivate fan curve control and restore automatic fan mode."""
-    g_state = _get_gpu_state(gpu_index)
+    _get_gpu_state(gpu_index)
 
-    # Stop poller
-    if g_state.get("fan_poller_task"):
-        g_state["fan_poller_task"].cancel()
-        with suppress(asyncio.CancelledError):
-            await g_state["fan_poller_task"]
-        g_state["fan_poller_task"] = None
-
-    g_state["fan_curve"] = None
-    g_state["fan_curve_active"] = False
-
-    ok, msg = await _run(reset_fan, gpu_index)
-    if not ok:
-        log.warning("Fan reset warning: %s", msg)
+    # Stop the poller, clear state, restore automatic fan control, and clear
+    # the persisted curve so it is not re-applied on the next server start.
+    await _deactivate_fan_curve(gpu_index, reset_hardware=True)
 
     return {"ok": True}