release: 1.1.0: Domain-admin role and internal/web package split

The first MINOR after 1.0.0: send-only DMARC guidance in the panel, AGPL packaging on every page, and an internal split of `internal/web` ahead of domain-admin work. Upgrading runs one SQLite migration (empty defaults; existing DNS guidance is unchanged until you set a report address).
Changed:
  - `internal/web` split into subpackages (`web/view`, `web/auth`, `web/validate`,
Added:
  - panel: DMARC guidance for send-only relays — the suggested `_dmarc` record
  - AGPL packaging hygiene: [NOTICE](NOTICE) names the copyright holder and the
  - [docs/roadmap.md](docs/roadmap.md) — candidate item **visual-style** (panel

Full detail: CHANGELOG.md (1.1.0).

internal/store/migrations/0004_dmarc_report_email.sql

@@ -0,0 +1,5 @@
+-- Optional DMARC aggregate-report destination (rua=) for the panel administrator
+-- and per-domain overrides. NULL dmarc_rua on a domain means inherit the profile.
+
+ALTER TABLE admin ADD COLUMN dmarc_report_email TEXT NOT NULL DEFAULT '';
+ALTER TABLE domains ADD COLUMN dmarc_rua TEXT;