refactor: replace magic indices with RtorrentField enum for type-safe parsing

Cargo.lock

@@ -310,6 +310,7 @@ dependencies = [
  "serde_json",
  "shared",
  "sqlx",
+ "strum",
  "thiserror 2.0.18",
  "time",
  "tokio",
@@ -544,7 +545,7 @@ version = "4.5.55"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "a92793da1a46a5f2a02a6f4c46c6496b28c43638adea8306fcb0caa1634f24e5"
 dependencies = [
- "heck",
+ "heck 0.5.0",
  "proc-macro2",
  "quote",
  "syn 2.0.114",
@@ -1536,6 +1537,12 @@ dependencies = [
  "hashbrown 0.15.5",
 ]
 
+[[package]]
+name = "heck"
+version = "0.4.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "95505c38b4572b2d910cecb0281560f54b440a19336cbbcb27bf6ce6adc6f5a8"
+
 [[package]]
 name = "heck"
 version = "0.5.0"
@@ -3703,7 +3710,7 @@ checksum = "19a9c1841124ac5a61741f96e1d9e2ec77424bf323962dd894bdb93f37d5219b"
 dependencies = [
  "dotenvy",
  "either",
- "heck",
+ "heck 0.5.0",
  "hex",
  "once_cell",
  "proc-macro2",
@@ -3846,6 +3853,28 @@ version = "0.11.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "7da8b5736845d9f2fcb837ea5d9e2628564b3b043a70948a3f0b778838c5fb4f"
 
+[[package]]
+name = "strum"
+version = "0.25.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "290d54ea6f91c969195bdbcd7442c8c2a2ba87da8bf60a7ee86a235d4bc1e125"
+dependencies = [
+ "strum_macros",
+]
+
+[[package]]
+name = "strum_macros"
+version = "0.25.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "23dc1fa9ac9c169a78ba62f0b841814b7abae11bdd047b9c58f893439e309ea0"
+dependencies = [
+ "heck 0.4.1",
+ "proc-macro2",
+ "quote",
+ "rustversion",
+ "syn 2.0.114",
+]
+
 [[package]]
 name = "subtle"
 version = "2.6.1"