feat: add support for Ntfy notification provider

[Wikid82]

• Updated the list of supported notification provider types to include 'ntfy'.
• Modified the notification settings UI to accommodate the Ntfy provider, including form fields for topic URL and access token.
• Enhanced localization files to include translations for Ntfy-related fields in German, English, Spanish, French, and Chinese.
• Implemented tests for the Ntfy notification provider, covering form rendering, CRUD operations, payload contracts, and security measures.
• Updated existing tests to account for the new Ntfy provider in various scenarios.

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[github-actions]

✅ Supply Chain Verification Results

✅ PASSED

📦 SBOM Summary

• Components: 1483

🔍 Vulnerability Scan

Severity	Count
🔴 Critical	0
🟠 High	0
🟡 Medium	4
🟢 Low	2
Total	6

📎 Artifacts

• SBOM (CycloneDX JSON) and Grype results available in workflow artifacts

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[codecov]

Codecov Report

❌ Patch coverage is 97.22222% with 1 line in your changes missing coverage. Please review.

Files with missing lines	Patch %	Lines
frontend/src/pages/Notifications.tsx	90.90%	1 Missing ⚠️

📢 Thoughts on this report? Let us know!

[Copilot]

Pull request overview

This PR adds Ntfy as a first-class notification provider across the backend dispatch layer, API validation, frontend settings UI, localization, and test suites—along with some dependency/security-maintenance updates.

Changes:

• Add ntfy to supported provider types and enable JSON-template-based dispatch with optional Bearer token auth.
• Extend the Notifications settings UI + i18n strings to support Ntfy topic URL and access token input.
• Add/adjust Playwright + unit tests for Ntfy provider behavior, payload contract, and token non-exposure.

Reviewed changes

Copilot reviewed 35 out of 39 changed files in this pull request and generated 1 comment.

Show a summary per file

File	Description
tests/settings/ntfy-notification-provider.spec.ts	New E2E suite covering Ntfy UI, CRUD, payload, and token security.
tests/settings/notifications.spec.ts	Updates provider type dropdown expectations to include Ntfy.
tests/settings/notifications-payload.spec.ts	Extends payload matrix tests to include Ntfy token + url contract.
package-lock.json	Updates KaTeX dev dependency version.
frontend/src/pages/tests/Notifications.test.tsx	Updates mocked supported provider types and option assertions for Ntfy.
frontend/src/pages/Notifications.tsx	Adds Ntfy UI support (labels/placeholders) and treats Ntfy as token-capable + JSON-template-capable.
frontend/src/locales/zh/translation.json	Adds Ntfy strings.
frontend/src/locales/fr/translation.json	Adds Ntfy strings.
frontend/src/locales/es/translation.json	Adds Ntfy strings.
frontend/src/locales/en/translation.json	Adds Ntfy strings.
frontend/src/locales/de/translation.json	Adds Ntfy strings.
frontend/src/components/tests/SecurityNotificationSettingsModal.test.tsx	Updates supported provider options assertion to include Ntfy.
frontend/src/api/notifications.ts	Adds ntfy to supported types and includes it in token-handling sanitization.
frontend/package.json	Bumps i18next, react-i18next, lucide-react versions.
frontend/package-lock.json	Locks bumped frontend dependency versions (and related transitive bumps).
docs/reports/qa_report_ntfy_notifications.md	Adds QA/security audit report for Ntfy provider.
docs/issues/ntfy-notification-provider-manual-testing.md	Adds a manual test plan for Ntfy provider.
docs/features/notifications.md	Documents Ntfy as a supported provider with setup + template examples.
docs/features.md	Updates marketing-level feature summary to include Ntfy and broader provider list.
backend/internal/services/notification_service_test.go	Adds unit tests for Ntfy support + feature flag behavior + JSON template support.
backend/internal/services/notification_service_json_test.go	Adds JSON payload send tests for Ntfy including Bearer auth + required message field validation.
backend/internal/services/notification_service.go	Implements Ntfy dispatch enablement flag, payload validation, and Bearer auth header behavior; fixes token clearing behavior.
backend/internal/notifications/router_test.go	Adds routing flag test coverage for Ntfy.
backend/internal/notifications/router.go	Routes Ntfy through Notify engine based on feature flag.
backend/internal/notifications/http_wrapper_test.go	Updates outbound header allowlist test to account for Authorization header.
backend/internal/notifications/http_wrapper.go	Allows outbound Authorization header (needed for Ntfy Bearer auth).
backend/internal/notifications/feature_flags.go	Adds feature.notifications.service.ntfy.enabled constant.
backend/internal/api/handlers/notification_provider_handler.go	Allows ntfy provider type and preserves token on update when omitted.
backend/internal/api/handlers/auth_handler.go	Comment formatting adjustment (no behavior change).
backend/go.sum	Updates go-toml checksum entries.
backend/go.mod	Bumps indirect dependency github.com/pelletier/go-toml/v2.
SECURITY.md	Updates vulnerability ledger content + review date.
Dockerfile	Bumps caddy-security plugin version.
CHANGELOG.md	Adds release notes for Ntfy provider and a related Pushover token bugfix note.
.grype.yaml	Removes outdated suppressions and retains current vulnerability suppressions.
.github/workflows/docker-build.yml	Runs docker build workflow on development branch pushes as well as main.

Files not reviewed (1)

• frontend/package-lock.json: Language not supported