fix: improve mbox patch parser resilience for optional tag fallback

- Use mailparse crate to handle RFC 2047 encoded-words (Q/B encoding)
  and RFC 2822 header folding in Subject and From headers
- Fix email signature separator check: use exact match 'line == "-- "'
  instead of starts_with to avoid false positives on body lines
- Remove dead/incorrect asctime parsing in committer date extraction;
  simplify to always return None (falls back to author_timestamp)

1 files changed, 1 insertions, 0 deletions

diff --git a/Cargo.toml b/Cargo.toml
index 71de413..63786cd 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -24,6 +24,7 @@ directories = "6.0.0"
 futures = "0.3.31"
 git2 = "0.20.2"
 indicatif = "0.18.0"
+mailparse = "0.16.1"
 nostr = { version = "0.44.1", features = ["nip49"] }
 nostr-connect = "0.44.0"
 nostr-database = "0.44.0"