fix: Gitea Traefik routing and connection pool optimization

- Remove middleware reference from Gitea Traefik labels (caused routing issues)
- Optimize Gitea connection pool settings (MAX_IDLE_CONNS=30, authentication_timeout=180s)
- Add explicit service reference in Traefik labels
- Fix intermittent 504 timeouts by improving PostgreSQL connection handling

Fixes Gitea unreachability via git.michaelschiemer.de

deployment/ansible/playbooks/install-docker.yml

@@ -0,0 +1,92 @@
+---
+- name: Install Docker on Production Server
+  hosts: production
+  become: yes
+  gather_facts: yes
+
+  tasks:
+    - name: Install prerequisites
+      ansible.builtin.apt:
+        name:
+          - ca-certificates
+          - curl
+        state: present
+        update_cache: yes
+
+    - name: Create keyrings directory
+      ansible.builtin.file:
+        path: /etc/apt/keyrings
+        state: directory
+        mode: '0755'
+
+    - name: Detect distribution (Debian or Ubuntu)
+      ansible.builtin.set_fact:
+        docker_distribution: "{{ 'debian' if ansible_distribution == 'Debian' else 'ubuntu' }}"
+      changed_when: false
+
+    - name: Add Docker GPG key
+      ansible.builtin.shell:
+        cmd: |
+          curl -fsSL https://download.docker.com/linux/{{ docker_distribution }}/gpg -o /etc/apt/keyrings/docker.asc
+          chmod a+r /etc/apt/keyrings/docker.asc
+        creates: /etc/apt/keyrings/docker.asc
+
+    - name: Add Docker repository
+      ansible.builtin.shell:
+        cmd: |
+          echo "deb [arch=$(dpkg --print-architecture) signed-by=/etc/apt/keyrings/docker.asc] https://download.docker.com/linux/{{ docker_distribution }} $(. /etc/os-release && echo "$VERSION_CODENAME") stable" | tee /etc/apt/sources.list.d/docker.list > /dev/null
+        creates: /etc/apt/sources.list.d/docker.list
+
+    - name: Update apt cache after adding Docker repo
+      ansible.builtin.apt:
+        update_cache: yes
+
+    - name: Install Docker packages
+      ansible.builtin.apt:
+        name:
+          - docker-ce
+          - docker-ce-cli
+          - containerd.io
+          - docker-buildx-plugin
+          - docker-compose-plugin
+        state: present
+
+    - name: Start and enable Docker service
+      ansible.builtin.systemd:
+        name: docker
+        state: started
+        enabled: yes
+
+    - name: Add deploy user to docker group
+      ansible.builtin.user:
+        name: "{{ ansible_user | default('deploy') }}"
+        groups: docker
+        append: yes
+
+    - name: Verify Docker installation
+      ansible.builtin.command: docker --version
+      register: docker_version
+      changed_when: false
+
+    - name: Display Docker version
+      ansible.builtin.debug:
+        msg: "Docker installed successfully: {{ docker_version.stdout }}"
+
+    - name: Verify Docker Compose installation
+      ansible.builtin.command: docker compose version
+      register: compose_version
+      changed_when: false
+
+    - name: Display Docker Compose version
+      ansible.builtin.debug:
+        msg: "Docker Compose installed successfully: {{ compose_version.stdout }}"
+
+    - name: Run Docker hello-world test
+      ansible.builtin.command: docker run --rm hello-world
+      register: docker_test
+      changed_when: false
+
+    - name: Display Docker test result
+      ansible.builtin.debug:
+        msg: "Docker is working correctly!"
+      when: "'Hello from Docker!' in docker_test.stdout"