feat: ship Tier 1 — auth, authz, rate limits, real notifications, CSV import, billing, backups/DR, privacy

Closes every block in docs/TIER1_PLAN.md from the Claude-scope side. The
homelab / cloud setup steps (SES verification, restore drill, lawyer-
drafted ToS) remain operator-owned but are unblocked.

Block A — Authentication
- Migration 0003: password_hash, email_verified, email_verification_tokens,
  password_reset_tokens, refresh_tokens (with replaced_by family chain).
- Bcrypt hasher, HS256 JWT signer, single-use refresh tokens with rotation
  + replay-detection (revokes the family on reuse).
- /auth/signup, /login, /refresh, /logout, /verify-email,
  /forgot-password, /reset-password — enumeration-safe.
- requireAuth middleware + GET /me.
- Frontend useAuth/useApi with auto-refresh-on-401, login/signup/verify/
  forgot/reset pages, route-guard middleware.

Block B — Authorisation
- EventRepo.GetForHost; Update/Delete scoped by host_id.
- All host routes behind requireAuth + ownership; cross-tenant returns
  404 (no enumeration). ?host_id removed.
- WS auth via short-lived single-use tickets (POST /auth/ws-ticket).
- Tests: TestCrossTenantIsolation — 9 probes.

Block C — Rate limiting
- Redis sliding-window via Lua (atomic ZADD+ZCARD+PEXPIRE).
- Per-route limits matching the plan (signup IP, login IP+email, RSVP/
  access by token, events/guests/tokens by user_id).
- 429 with Retry-After header and JSON body.
- Auth lockout: 5 failed logins → account locked, only password reset
  clears it.
- Frontend: useErrMessage normalises 429 + locked messaging.

Block D — Real notifications
- Migration 0004: provider_message_id, bounce_type, complained columns
  + unsubscribes (CITEXT) suppression table.
- Branded HTML + plaintext templates for verification, reset, invitation,
  confirmation, reminder. Per-page templates avoid html/template's
  contextual-escape collisions.
- Senders: SESv2, Twilio (SMS), SMTP (Mailpit-friendly), Resend HTTP.
- PickEmailSender priority Resend > SMTP > SES > Log — system boots
  cleanly in dev with Mailpit; production flips one env var.
- Webhook endpoints (Twilio status + SES SNS) — bounces add to suppression;
  signature verification stubbed pending creds.
- Auto-send: POST /tokens publishes invitation.send; notifier renders +
  delivers via the configured backend; suppression list honoured.
- Bulk + per-row invitation flow: POST /events/{id}/guests/invitations/bulk
  returns per-guest tokens so phone-only guests can be SMS'd manually.
- Unsubscribe: signed HMAC token (no TTL) + /unsubscribe/[token] page.
- WhatsApp Option A+: wa.me click-to-chat wizard with per-guest progress
  tracking, isLikelyE164 validation, edit-from-wizard.
- Token rotate (POST /tokens/rotate) invalidates the old URL — used by
  the regenerate-link flow.
- Mailpit added to docker-compose for dev inbox.

Block E — CSV import
- Streaming parser: tolerant header detection, UTF-8 BOM + UTF-16 LE/BE
  decoding, row-level validation, 5,000-row cap.
- Strict E.164 phone validation with helpful error message.
- POST /preview + /import + GET /template; preview UI on event page;
  atomic per-batch with dedup on existing emails.

Phone capture across UI
- PhoneInput component: country picker (~50 ISO codes) + national input +
  live E.164 preview + inline length validation.
- Used in Add Guest and Edit Guest modals. Smart paste-handling extracts
  country code from full E.164 strings.

Block F — Billing (Stripe)
- Migration 0005: subscriptions table (user_id → tier/status/period_end +
  Stripe customer/sub ids). Partial unique index keeps one granting sub
  per user.
- internal/billing: Tier + Limits model (Free 1/50, Pro 10/1000, Business
  ∞/5000), Stripe SDK wrapper with IgnoreAPIVersionMismatch for newer
  account API versions.
- /billing/checkout-session, /billing/portal, /billing/status,
  /webhooks/stripe (signature-verified, lifecycle events).
- Tier enforcement: 402 on POST /events, /guests, /import with
  {error, reason, tier, used, limit, upgrade_url} body.
- Frontend: useBilling composable, /dashboard/billing page (current plan,
  usage bars, tier cards), global UpgradeModal triggered by useApi's
  402 interceptor.
- Customer portal kept for self-service cancel/payment-method changes.

Block G — Backups & DR (application side)
- Every migration has a tested .down.sql.
- TestMigrationRoundtrip applies all ups → all downs → all ups against a
  fresh container; catches asymmetric down migrations.
- cmd/restore-verify: 28-check post-restore invariant tool (schema
  presence, no orphans across 10 FK relationships, email uniqueness,
  single-active subscription, row-count snapshot).
- docs/RUNBOOK_RESTORE.md: 9-step restore procedure with RTO/RPO
  targets, drill instructions, rollback path.

Block H — Privacy compliance (application side)
- Migration 0006: deleted_at + terms_accepted_at + privacy_policy_accepted_at
  on users. Partial index on email for live-only uniqueness.
- GET /me/data-export — synchronous JSON dump (user, events, guests,
  tokens, rsvps, access_logs, notifications).
- DELETE /me — soft-delete with PII scrub + refresh-token revocation;
  re-signup with same email works.
- POST /me/accept-terms — idempotent consent recording.
- Frontend /privacy + /terms placeholder pages with substantive (pending
  legal review) copy; footer links; signup terms checkbox; TermsGateModal
  for accounts created before the rollout; export + delete buttons on
  /dashboard/billing.

Tests
- All migrations verified up/down/up.
- Integration suite: TestE2EHappyPath, TestAuthFlow, TestCrossTenantIsolation,
  TestRateLimitSignup, TestLoginLockout, TestUnsubscribeFlow,
  TestSESBounceWebhook, TestTwilioStatusWebhook, TestCsvImportFlow,
  TestCsvImportAtomicRollback, TestBulkIssueInvitations, TestBulkIssueExplicitSubset,
  TestTokenIssuePublishesInvitation, TestTokenIssueWithoutGuestEmailSkipsInvitation,
  TestGuestUpdate, TestGuestDelete, TestTokenRotate, TestSMTPSenderAgainstMailpit,
  TestFreeTierEventLimit, TestFreeTierGuestLimit, TestBusinessTierBypassesLimits,
  TestDataExport, TestDeleteMe, TestAcceptTerms, TestMigrationRoundtrip.
  Full suite runs in ~120s against real Postgres + NATS + Redis + Mailpit.
- Unit suite green across internal/auth, internal/csvimport,
  internal/notification, internal/ratelimit, internal/domain.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

internal/notification/templates.go

@@ -0,0 +1,116 @@
+package notification
+
+import (
+	"bytes"
+	"embed"
+	"fmt"
+	htmltemplate "html/template"
+	"io/fs"
+	"path"
+	"strings"
+	texttemplate "text/template"
+)
+
+//go:embed templates
+var templatesFS embed.FS
+
+// TemplateName names one of the email templates. There must be a
+// matching `<name>.html` and `<name>.txt` under templates/.
+type TemplateName string
+
+const (
+	TmplVerification  TemplateName = "verification"
+	TmplPasswordReset TemplateName = "reset"
+	TmplInvitation    TemplateName = "invitation"
+	TmplConfirmation  TemplateName = "confirmation"
+	TmplReminder      TemplateName = "reminder"
+)
+
+// Templates renders branded transactional emails for both HTML and
+// plaintext bodies. Loaded once at construction; thread-safe afterwards.
+//
+// Each page-level HTML template gets its own *html/template.Template
+// holding a copy of the `base.html` partial. This avoids html/template's
+// per-template contextual-escape pass interfering between pages that all
+// define a sibling named "body".
+type Templates struct {
+	html map[string]*htmltemplate.Template // page-name (no ext) -> root
+	text *texttemplate.Template
+}
+
+func NewTemplates() (*Templates, error) {
+	root, err := fs.Sub(templatesFS, "templates")
+	if err != nil {
+		return nil, fmt.Errorf("templates fs: %w", err)
+	}
+
+	baseHTML, err := fs.ReadFile(root, "base.html")
+	if err != nil {
+		return nil, fmt.Errorf("read base.html: %w", err)
+	}
+
+	out := &Templates{
+		html: make(map[string]*htmltemplate.Template),
+		text: texttemplate.New("__root__"),
+	}
+
+	walk := func(p string, d fs.DirEntry, _ error) error {
+		if d == nil || d.IsDir() {
+			return nil
+		}
+		base := path.Base(p)
+		if base == "base.html" {
+			return nil // partial — folded into each page template below
+		}
+		b, err := fs.ReadFile(root, p)
+		if err != nil {
+			return err
+		}
+		switch {
+		case strings.HasSuffix(p, ".html"):
+			name := strings.TrimSuffix(base, ".html")
+			t := htmltemplate.New(name)
+			if _, err := t.Parse(string(baseHTML)); err != nil {
+				return fmt.Errorf("parse _base for %s: %w", p, err)
+			}
+			if _, err := t.Parse(string(b)); err != nil {
+				return fmt.Errorf("parse %s: %w", p, err)
+			}
+			out.html[name] = t
+		case strings.HasSuffix(p, ".txt"):
+			if _, err := out.text.New(base).Parse(string(b)); err != nil {
+				return fmt.Errorf("parse %s: %w", p, err)
+			}
+		}
+		return nil
+	}
+	if err := fs.WalkDir(root, ".", walk); err != nil {
+		return nil, err
+	}
+	return out, nil
+}
+
+// Render returns (htmlBody, textBody) for the named template using data.
+func (t *Templates) Render(name TemplateName, data map[string]any) (htmlBody, textBody string, err error) {
+	if data == nil {
+		data = map[string]any{}
+	}
+	if _, ok := data["Subject"]; !ok {
+		data["Subject"] = "GuestGuard"
+	}
+
+	htmlTpl, ok := t.html[string(name)]
+	if !ok {
+		return "", "", fmt.Errorf("unknown html template %q", name)
+	}
+
+	var hBuf, tBuf bytes.Buffer
+	// Each page-root template's entry point is "base" (defined by base.html).
+	if err := htmlTpl.ExecuteTemplate(&hBuf, "base", data); err != nil {
+		return "", "", fmt.Errorf("render html %s: %w", name, err)
+	}
+	if err := t.text.ExecuteTemplate(&tBuf, string(name)+".txt", data); err != nil {
+		return "", "", fmt.Errorf("render text %s: %w", name, err)
+	}
+	return hBuf.String(), tBuf.String(), nil
+}