release: 0.1.0: Phases 0-11: panel, Postfix/DKIM, milter, backup, Docker image

Initial feature-complete implementation of the v1.0 specification (phases 0-11 of `docs/implementation-plan.md`).
Added:
  - Panel (Go, single static binary) with SQLite persistence, one-time
  - Domain management with per-domain DKIM (RSA-2048, generated in pure Go) and
  - Application (sender identity) management: SASL credentials via `sasldb2`,
  - Full Postfix relay config generated from env at container start: SMTPS 465,
  - Journal milter (pure Go, `go-milter`) recording every send to `send_log`;
  … (6 more in CHANGELOG)

Full detail: CHANGELOG.md (0.1.0).

.gitattributes

@@ -0,0 +1,32 @@
+# Normalize all text files to LF in the working tree.
+# Critical: shell scripts, Dockerfile and configs run inside a Linux container
+# and MUST NOT get CRLF line endings (a "#!/bin/sh\r" shebang breaks startup).
+* text=auto eol=lf
+
+# Explicit LF for files copied into / executed in the image.
+*.go        text eol=lf
+*.sh        text eol=lf
+*.conf      text eol=lf
+*.cf        text eol=lf
+*.cnf       text eol=lf
+*.yml       text eol=lf
+*.yaml      text eol=lf
+*.md        text eol=lf
+*.txt       text eol=lf
+*.js        text eol=lf
+*.html      text eol=lf
+*.tmpl      text eol=lf
+Dockerfile  text eol=lf
+Makefile    text eol=lf
+go.mod      text eol=lf
+go.sum      text eol=lf
+LICENSE     text eol=lf
+
+# Binary assets — never touch.
+*.png binary
+*.jpg binary
+*.jpeg binary
+*.gif binary
+*.ico binary
+*.woff binary
+*.woff2 binary