chore: add GitHub automation and fix rand vulnerability

GitHub Actions:
- Add Dependabot for weekly dependency updates (cargo, github-actions)
- Add PR labeler workflow with file-based auto-labeling
- Add issue/PR templates (bug report, feature request, PR template)
- Fix release.yml artifact paths and labeler.yml config syntax
Security:
- Upgrade rand 0.8 → 0.10 to fix RUSTSEC-2026-0097 unsoundness
- Update screenshot.rs for rand 0.10 API (thread_rng → rng, gen_range → random_range)

Cargo.toml

@@ -3,6 +3,8 @@ name = "rustlock"
 version = "0.1.0"
 edition = "2021"
 license = "GPL-3.0-or-later"
+authors = ["Jory Severijnse"]
+description = "A high-performance Wayland screen locker"
 
 [dependencies]
 smithay-client-toolkit = { version = "0.19", default-features = false, features = ["calloop", "xkbcommon"] }
@@ -27,7 +29,7 @@ zbus = { version = "5.14", default-features = false, features = ["tokio"] }
 mpris = "2.0"
 tokio = { version = "1.51", default-features = false, features = ["rt", "rt-multi-thread", "macros", "time", "sync"] }
 num-traits = { version = "0.2" }
-rand = { version = "0.8" }
+rand = { version = "0.10" }
 reqwest = { version = "0.12", default-features = false, features = ["blocking", "rustls-tls"], optional = true }
 image = { version = "0.25", default-features = false, features = ["png", "jpeg"] }
     fastblur = "0.1"