feat: configurable MAX_SESSIONS via N8N_MCP_MAX_SESSIONS env var (v2.28.4) (#469)

* fix: n8n_test_workflow webhookId resolution and form handling (v2.28.2)

## Bug Fixes

- **webhookId Resolution**: Fixed trigger handlers using `node.id` instead of
  `node.webhookId` for building webhook URLs. This caused 404 errors when
  nodes had custom IDs.

- **Chat Trigger URL**: Fixed chat triggers using wrong URL pattern. Now
  correctly uses `/webhook/<webhookId>/chat` endpoint.

- **Form Content-Type**: Fixed form triggers failing with "Expected
  multipart/form-data" error by switching to proper multipart encoding.

## Enhancements

- **Form Field Types**: Added support for all n8n form field types (text,
  textarea, email, number, password, date, dropdown, checkbox, file, hidden)

- **Checkbox Arrays**: Automatically converts arrays to `field[]` format

- **Helpful Warnings**: Reports missing required fields with names and labels

- **Error Hints**: Provides complete field structure on failure

Conceived by Romuald Członkowski - https://www.aiadvisors.pl/en

🤖 Generated with [Claude Code](https://claude.com/claude-code)

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

* fix: address code review issues for form trigger improvements

- Add form-data as direct dependency (was only in devDependencies)
- Add TypeScript interfaces (FormFieldValue, FormFieldOption) replacing any types
- Add FORM_FIELD_TYPES constants for type-safe switch statements
- Add isValidBase64() validation for file uploads with size limits
- Add MAX_FILE_SIZE_BYTES (10MB) constant with validation
- Update form-handler.test.ts for FormData instead of JSON
- Update trigger-detector.test.ts for chat URL /chat suffix

Conceived by Romuald Członkowski - www.aiadvisors.pl/en

🤖 Generated with [Claude Code](https://claude.com/claude-code)

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

* feat: configurable MAX_SESSIONS via N8N_MCP_MAX_SESSIONS env var (v2.28.3) (#468)

Make MAX_SESSIONS limit configurable for multi-tenant SaaS deployments.

- Add N8N_MCP_MAX_SESSIONS environment variable (default: 100)
- Include safety floor with Math.max(1, ...) to prevent invalid configs
- Update documentation in LIBRARY_USAGE.md, SESSION_PERSISTENCE.md
- Update CLAUDE.md and CHANGELOG.md

Fixes #468

Conceived by Romuald Członkowski - https://www.aiadvisors.pl/en

🤖 Generated with [Claude Code](https://claude.com/claude-code)

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

* fix: add QEMU setup for multi-arch Docker builds

Add docker/setup-qemu-action@v3 before Buildx setup to enable
proper QEMU emulation for linux/arm64 builds on GitHub Actions.

Fixes CI Docker build failure with "execve: No such file or directory"

🤖 Generated with [Claude Code](https://claude.com/claude-code)

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

---------

Co-authored-by: Claude <noreply@anthropic.com>
Co-authored-by: Romuald Członkowski <romualdczlonkowski@MacBook-Pro-Romuald.local>

tests/unit/http-server/session-persistence.test.ts

@@ -427,7 +427,7 @@ describe('SingleSessionHTTPServer - Session Persistence', () => {
     });
 
     it('should respect MAX_SESSIONS limit during restore', () => {
-      // Create 99 existing sessions (MAX_SESSIONS is 100)
+      // Create 99 existing sessions (MAX_SESSIONS defaults to 100, configurable via N8N_MCP_MAX_SESSIONS env var)
       const serverAny = server as any;
       const now = new Date();
       for (let i = 0; i < 99; i++) {