extract background tasks into worker binary

Move auto_scheduler, library_sync, broadcast_poller, webhook_consumer
from presentation/background/ into crates/worker/src/jobs/.
Presentation is now a pure HTTP server.

crates/worker/Cargo.toml

@@ -0,0 +1,35 @@
+[package]
+name = "worker"
+version = "0.1.0"
+edition = "2024"
+
+[[bin]]
+name = "k-tv-worker"
+path = "src/main.rs"
+
+[features]
+default = ["sqlite", "jellyfin"]
+sqlite = ["dep:adapter-sqlite", "infra-wiring/sqlite"]
+jellyfin = ["dep:adapter-jellyfin"]
+local-files = ["dep:adapter-local-files"]
+
+[dependencies]
+domain = { workspace = true }
+application = { workspace = true }
+infra-wiring = { workspace = true }
+adapter-sqlite = { workspace = true, optional = true }
+adapter-auth = { workspace = true }
+adapter-jellyfin = { workspace = true, optional = true }
+adapter-local-files = { workspace = true, optional = true }
+adapter-event-publisher = { workspace = true }
+tokio = { workspace = true }
+tracing = { workspace = true }
+tracing-subscriber = { workspace = true }
+reqwest = { workspace = true }
+serde_json = { workspace = true }
+chrono = { workspace = true }
+uuid = { workspace = true }
+async-trait = { workspace = true }
+handlebars = "6"
+dotenvy = "0.15"
+anyhow = "1"