feat: v0.2.0 optimization refactor and docs

- Refactor core traversal to single-pass O(N) tree construction
- Optimize CSV output using `csv` crate for robust escaping
- Optimize JSON output with zero-copy serialization
- Add MANUAL.md
- Bump version to 0.2.0
- Remove walkdir dependency

Cargo.lock

@@ -285,6 +285,16 @@ version = "0.7.7"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "c3e64b0cc0439b12df2fa678eae89a1c56a529fd067a9115f7827f1fffd22b32"
 
+[[package]]
+name = "clap_mangen"
+version = "0.2.31"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "439ea63a92086df93893164221ad4f24142086d535b3a0957b9b9bea2dc86301"
+dependencies = [
+ "clap",
+ "roff",
+]
+
 [[package]]
 name = "colorchoice"
 version = "1.0.4"
@@ -868,6 +878,12 @@ dependencies = [
  "syn 1.0.109",
 ]
 
+[[package]]
+name = "roff"
+version = "0.2.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "88f8660c1ff60292143c98d08fc6e2f654d722db50410e3f3797d40baaf9d8f3"
+
 [[package]]
 name = "rust_decimal"
 version = "1.40.0"
@@ -999,13 +1015,14 @@ checksum = "e3a9fe34e3e7a50316060351f37187a3f546bce95496156754b601a5fa71b76e"
 
 [[package]]
 name = "sized"
-version = "0.1.0"
+version = "0.2.0"
 dependencies = [
  "atty",
  "byte-unit",
  "chrono",
  "clap",
  "clap_complete",
+ "clap_mangen",
  "colored",
  "comfy-table",
  "csv",
@@ -1015,7 +1032,6 @@ dependencies = [
  "serde",
  "serde_json",
  "strum",
- "walkdir",
 ]
 
 [[package]]