feat: email connector (#157)

* new: add email connection shell

* new: add secure & insecure smtp

* new: read email

* new: more email logic

* feat: automatically reply

* feat: poc email response

* feat: introduce email concurrency and reply functionality

* feat: html replies

* refactor: make email.go legible

* feat: add email connection docs

* fix: startup error handling and dial error

go.mod

@@ -32,7 +32,10 @@ require (
 	mvdan.cc/xurls/v2 v2.6.0
 )
 
+require github.com/JohannesKaufmann/dom v0.2.0 // indirect
+
 require (
+	github.com/JohannesKaufmann/html-to-markdown/v2 v2.3.2
 	github.com/PuerkitoBio/goquery v1.10.3 // indirect
 	github.com/andybalholm/brotli v1.1.1 // indirect
 	github.com/andybalholm/cascadia v1.3.3 // indirect
@@ -45,6 +48,10 @@ require (
 	github.com/bytedance/sonic/loader v0.2.4 // indirect
 	github.com/cloudwego/base64x v0.1.5 // indirect
 	github.com/dlclark/regexp2 v1.11.5 // indirect
+	github.com/emersion/go-imap/v2 v2.0.0-beta.5 // indirect
+	github.com/emersion/go-message v0.18.2 // indirect
+	github.com/emersion/go-sasl v0.0.0-20241020182733-b788ff22d5a6 // indirect
+	github.com/emersion/go-smtp v0.22.0 // indirect
 	github.com/gabriel-vasile/mimetype v1.4.9 // indirect
 	github.com/gin-contrib/sse v1.1.0 // indirect
 	github.com/gin-gonic/gin v1.10.0 // indirect
@@ -60,6 +67,7 @@ require (
 	github.com/gofiber/utils v1.1.0 // indirect
 	github.com/golang/groupcache v0.0.0-20241129210726-2c02b8208cf8 // indirect
 	github.com/golang/protobuf v1.5.4 // indirect
+	github.com/gomarkdown/markdown v0.0.0-20250311123330-531bef5e742b
 	github.com/google/go-cmp v0.7.0 // indirect
 	github.com/google/go-querystring v1.1.0 // indirect
 	github.com/google/pprof v0.0.0-20250423184734-337e5dd93bb4 // indirect