fix(deps): enable mail-parser full_encoding for legacy CJK charsets

Without the `full_encoding` feature, mail-parser ships only the UTF-8 /
ASCII decoders, so a message whose body or encoded-word headers use a
legacy charset (ISO-2022-JP, Shift-JIS, EUC-JP, GBK, Big5, windows-*) is
passed through undecoded and renders as mojibake in `message read`.

These charsets are still widely used by Japanese bank / utility /
corporate senders. Enabling `full_encoding` pulls in encoding_rs and
restores the decoders, after which affected messages render correctly.

Listing (`envelope list`, `gmail messages list`) was unaffected because
it uses the header values already decoded by the Gmail API; only the
RAW-fetch + mail-parser path in `message read` was broken.

Co-authored-by: metrovoc <metrovoc@users.noreply.github.com>
Refs: #706

Cargo.lock

@@ -1402,6 +1402,7 @@ version = "0.11.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "d8a2420e9ce11c2b0583ca97ddff7ab2398c8a613154e9b72e3bafdbf767f1d7"
 dependencies = [
+ "encoding_rs",
  "hashify",
  "serde",
 ]

Cargo.toml

@@ -58,7 +58,7 @@ io-maildir = { version = "0.1", default-features = false, optional = true }
 io-smtp = { version = "0.1", default-features = false, optional = true }
 log = "0.4"
 mail-builder = "0.4"
-mail-parser = { version = "0.11", features = ["serde"], optional = true }
+mail-parser = { version = "0.11", features = ["full_encoding", "serde"], optional = true }
 mime_guess = { version = "2", optional = true }
 open = "5"
 pimalaya-cli = { version = "0.0.1", default-features = false, features = ["terminal", "table", "prompt", "wizard", "imap", "smtp", "jmap", "spinner"] }