feat(waf): Phase 1 — Migration + Service + Handler — v1.2.66

- Migration 0037: waf_configs-Tabelle (domain_id FK, enabled=false default,
  mode/paranoia_level/rule_exclusions/trusted_proxies/custom_rules)
- models/waf.go: WafConfig-Model
- services/waf/waf.go: Repo (List, GetByDomain, Upsert, ListEnabled)
- handlers/waf.go: GET /waf/configs, GET /waf/configs/:id, PUT /waf/configs/:id
  — GET liefert Default-Config (disabled) wenn noch kein Row existiert
- main.go: WafHandler registriert

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

internal/database/migrations/0037_waf.sql

@@ -0,0 +1,18 @@
+-- +goose Up
+CREATE TABLE IF NOT EXISTS waf_configs (
+    id              SERIAL PRIMARY KEY,
+    domain_id       BIGINT NOT NULL REFERENCES domains(id) ON DELETE CASCADE,
+    enabled         BOOLEAN  NOT NULL DEFAULT false,
+    mode            TEXT     NOT NULL DEFAULT 'detection'
+                             CHECK (mode IN ('detection','blocking')),
+    paranoia_level  INT      NOT NULL DEFAULT 1
+                             CHECK (paranoia_level BETWEEN 1 AND 4),
+    rule_exclusions TEXT[]   NOT NULL DEFAULT '{}',
+    trusted_proxies TEXT[]   NOT NULL DEFAULT '{}',
+    custom_rules    TEXT     NOT NULL DEFAULT '',
+    updated_at      TIMESTAMPTZ NOT NULL DEFAULT NOW(),
+    CONSTRAINT waf_configs_domain_unique UNIQUE (domain_id)
+);
+
+-- +goose Down
+DROP TABLE IF EXISTS waf_configs;