Add comprehensive documentation for CLICD features and operations

- Introduced Container Management documentation covering lifecycle operations, resource management, and console access.
- Added Dashboard documentation detailing metrics and related APIs.
- Created Host Report documentation summarizing host environment and resource status.
- Included Image Management documentation for template handling and management actions.
- Documented Networking and Routing features including NAT4 and IPv6 management.
- Added Security Alerts documentation outlining alert scenarios and API usage.
- Created Snapshot Management documentation for snapshot operations and scheduling.
- Documented Sub-user management for granting access to specific containers.
- Added Configuration guide detailing runtime settings and security recommendations.
- Created Installation guide for setting up CLICD with requirements and steps.
- Added Introduction and Quick Start guides for new users.
- Documented Upgrade process with version checking and pre-upgrade checklist.
- Created Deployment guide for service exposure and firewall recommendations.
- Added FAQ section addressing common questions and concerns.
- Documented Troubleshooting steps for common issues encountered.

docs/en/developer/release.md

@@ -0,0 +1,44 @@
+# Release Process
+
+CLICD installation and upgrade rely on GitHub Release artifacts. Use semantic version tags such as `v1.1.6`.
+
+## Version Number
+
+Check the version in:
+
+- `backend/internal/version/version.go`
+- `frontend/package.json`
+- Release tag.
+
+## Release Artifacts
+
+The installer first tries to download the Linux AMD64 archive:
+
+```text
+clicd-linux-amd64.tar.gz
+```
+
+In some cases, it may also try the standalone binary:
+
+```text
+clicd-linux-amd64
+```
+
+## Installer Behavior
+
+- `CLICD_VERSION=latest`: use GitHub `releases/latest`.
+- `CLICD_VERSION=vX.Y.Z`: download artifacts from the specified release tag.
+
+Example:
+
+```bash
+CLICD_VERSION=v1.1.6 sh install.sh
+```
+
+## Post-release Verification
+
+- The installer can download the new version.
+- `systemctl status clicd` is healthy.
+- `/api/version` returns the new version.
+- The web panel can load frontend assets.
+- Container list, task queue, and API Key pages open correctly.