🔦 Modernize flashlight for CSS/.NET 10

Bump to CounterStrikeSharp 1.0.371 and .NET 10, replace per-tick light
spawns with a parented light_barn, add plugin config, real unit tests,
and refresh CI plus docs.

Co-authored-by: Cursor <cursoragent@cursor.com>

docs/superpowers/plans/2026-07-21-flashlight-modernization.md

@@ -0,0 +1,61 @@
+# Flashlight Modernization Implementation Plan
+
+> **For agentic workers:** REQUIRED SUB-SKILL: Use superpowers:subagent-driven-development (recommended) or superpowers:executing-plans to implement this plan task-by-task. Steps use checkbox (`- [ ]`) syntax for tracking.
+
+**Goal:** Modernize the flashlight plugin to .NET 10 / CSS 1.0.371 with a parented `light_barn` implementation, config, real unit tests, fixed CI, and updated README.
+
+**Architecture:** Pure helpers in `FlashlightLogic` + config clamps in `FlashlightConfig`; plugin owns lifecycle and wires Use/command/events; one `CBarnLight` per active player, parented once, toggled via create/destroy.
+
+**Tech Stack:** .NET 10, CounterStrikeSharp.API 1.0.371, xUnit, GitHub Actions
+
+## Global Constraints
+
+- Target framework: `net10.0`
+- Package: `CounterStrikeSharp.API` `1.0.371`
+- `[MinimumApiVersion(371)]`
+- Module version: `0.1.0`
+- No per-tick entity create/spawn/teleport in steady state
+- Spec: `docs/superpowers/specs/2026-07-21-flashlight-modernization-design.md`
+
+---
+
+### Task 1: Project targets + pure logic + tests
+
+**Files:**
+- Modify: `Flashlight/Flashlight.csproj`
+- Modify: `Flashlight.Tests/Flashlight.Tests.csproj`
+- Create: `Flashlight/FlashlightConfig.cs`
+- Create: `Flashlight/FlashlightLogic.cs`
+- Create: `Flashlight/PlayerFlashlightState.cs`
+- Modify: `Flashlight.Tests/FlashlightLogicTests.cs`
+
+- [x] Retarget both projects to `net10.0`; bump CSS to `1.0.371`; bump test packages as needed
+- [x] Implement `FlashlightConfig` with defaults from the spec and a `Clamp()` method
+- [x] Implement pure `FlashlightLogic` helpers: try-toggle with cooldown, eye Z offset, origin from base+forward
+- [x] Replace smoke tests with tests against those helpers
+- [x] Run `dotnet test` and confirm pass
+
+### Task 2: Plugin rewrite (parented light_barn)
+
+**Files:**
+- Modify: `Flashlight/Flashlight.cs`
+- Delete or gut: `Flashlight/LogHelper.cs` (prefer `Logger`)
+
+- [x] Implement `BasePlugin, IPluginConfig<FlashlightConfig>`
+- [x] OnTick: Use-key edge + cooldown only when `AllowUseKey`
+- [x] Create/parent/enable `light_barn` once on toggle on; remove on toggle off
+- [x] Cleanup on death/spawn/team/disconnect/unload
+- [x] Keep `css_fl_toggle`
+- [x] Run `dotnet build` and confirm success
+
+### Task 3: CI + README
+
+**Files:**
+- Modify: `.github/workflows/build.yml`
+- Modify: `README.md`
+
+- [x] CI: .NET 10, restore, test, release build
+- [x] README: versions, parented light, config table, build/test, changelog 0.1.0
+- [x] Run `dotnet test` once more
+
+---