docs: comprehensive documentation improvement pass

Warnings: 16 → 1 (only external php.net intersphinx, unfixable)

Orphaned duplicates removed (8 files):
  actions, ansible, api, docker, executors, multiflexi-cli,
  opentelemetry, zabbix — all superseded by reference/ or integrations/

Legacy toctree: architecture, apps, commandline, configuration added
  to suppress orphan warnings while content is still valid

development.rst split into 4 stub pages:
  development/project-structure, contributing, testing,
  application-development — each now has real content

Broken images fixed in firstrun.rst:
  ../../doc/*.png → _static/images/screenshots/ (files copied from
  multiflexi-common/doc/)

Integration stubs filled:
  integrations/abraflexi.rst — packages, credential fields, UI features
  integrations/pohoda.rst — mServer credential fields, PHP usage example

CLI syntax: 21 files updated to namespace:action format
  runtemplate → run-template:*, credtype → credential-type:*,
  company assign-app → company-app:assign, --runtemplate= → --id=,
  application/company/job commands all get colon separator

README.md: created with build instructions, Debian package info,
  contributing guide, and related-projects table

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

Author: Vitexus

README.md

@@ -0,0 +1,95 @@
+# MultiFlexi Documentation
+
+[![Documentation Status](https://readthedocs.org/projects/multiflexi/badge/?version=latest)](https://multiflexi.readthedocs.io/en/latest/)
+[![Build Status](https://jenkins.vitexsoftware.cz/buildStatus/icon?job=multiflexi-doc-en)](https://jenkins.vitexsoftware.cz/job/multiflexi-doc-en/)
+
+English documentation for [MultiFlexi](https://multiflexi.eu) — a PHP-based task scheduling and automation framework for accounting and business system integrations.
+
+**Read online:** https://multiflexi.readthedocs.io/en/latest/
+
+## Contents
+
+- **Getting Started** — quickstart, installation, first-run setup
+- **Core Concepts** — system overview, data model, job lifecycle, credential management, execution architecture
+- **How-To Guides** — adding companies, installing applications, creating run templates, scheduling jobs, assigning credentials, debugging
+- **Integration Guides** — AbraFlexi, Pohoda, Zabbix, OpenTelemetry, Ansible, Kubernetes
+- **Reference** — REST API, CLI commands, configuration, application schema, executors, actions
+- **System Administration** — Docker deployment, systemd services, database maintenance, backup, upgrading
+- **Development** — architecture, project structure, application development, testing, contributing
+
+## Building Locally
+
+### Prerequisites
+
+```bash
+sudo apt install python3-sphinx python3-shibuya-sphinx-theme
+```
+
+Or with pip:
+
+```bash
+pip install -r requirements.txt
+```
+
+### Build HTML
+
+```bash
+make html
+# Output: build/html/index.html
+```
+
+### Build other formats
+
+```bash
+make epub    # EPUB e-book
+make latex   # LaTeX (requires texlive)
+make text    # Plain text
+```
+
+## Automatic Publishing
+
+Every push to `main` triggers a rebuild on [ReadTheDocs](https://multiflexi.readthedocs.io/) via GitHub Actions.
+
+## Debian Package
+
+The documentation is also distributed as a Debian package (`multiflexi-doc`) that installs the built HTML to `/usr/share/doc/multiflexi/html/`.
+
+```bash
+# Build the .deb
+dpkg-buildpackage -b --no-sign
+
+# Install
+sudo apt install ./multiflexi-doc_*.deb
+# Browse at http://localhost/multiflexi-doc/  (requires Apache or Nginx)
+```
+
+Apache configuration is enabled automatically on install.
+Nginx snippet is installed to `/usr/share/doc/multiflexi/multiflexi-doc.nginx`.
+
+## Documentation Standards
+
+See [AGENTS.md](AGENTS.md) for language, formatting, and content rules that apply to all contributions.
+
+Key rules:
+- English only; active voice; second person ("you")
+- reStructuredText (`.rst`) for all source files
+- Always specify language in code blocks
+- Provide working, copy-paste-ready examples
+- Only document released, implemented behaviour
+- Cross-check app/credential-type field docs against the [canonical JSON schemas](https://github.com/VitexSoftware/php-vitexsoftware-multiflexi-core)
+
+## Contributing
+
+1. Edit the relevant `.rst` file under `source/`
+2. Build locally and verify: `make html`
+3. Commit and push — ReadTheDocs rebuilds automatically
+
+## Related Projects
+
+| Project | Description |
+|---|---|
+| [MultiFlexi](https://github.com/VitexSoftware/MultiFlexi) | Main web application |
+| [multiflexi-cli](https://github.com/VitexSoftware/multiflexi-cli) | Command-line interface |
+| [multiflexi-tui](https://github.com/VitexSoftware/multiflexi-tui) | Terminal UI |
+| [php-vitexsoftware-multiflexi-core](https://github.com/VitexSoftware/php-vitexsoftware-multiflexi-core) | Core PHP library |
+| [multiflexi-api](https://github.com/VitexSoftware/multiflexi-api) | REST API server |

debian/multiflexi-doc.postinst.debhelper

@@ -0,0 +1,10 @@
+# Automatically added by dh_apache2/UNDECLARED
+if true; then
+	if [ -e /usr/share/apache2/apache2-maintscript-helper ] ; then
+		. /usr/share/apache2/apache2-maintscript-helper
+		for conf in multiflexi-doc  ; do
+			apache2_invoke enconf $conf  || exit 1
+		done
+	fi
+fi
+# End automatically added section

debian/multiflexi-doc.postrm.debhelper

@@ -0,0 +1,13 @@
+# Automatically added by dh_apache2/UNDECLARED
+if [ "$1" = "purge" ] ; then
+	if true; then
+		if [ -e /usr/share/apache2/apache2-maintscript-helper ] ; then
+			. /usr/share/apache2/apache2-maintscript-helper
+
+			for conf in multiflexi-doc  ; do
+				apache2_invoke disconf $conf  || exit 1
+			done
+		fi
+	fi
+fi
+# End automatically added section

debian/multiflexi-doc.prerm.debhelper

@@ -0,0 +1,13 @@
+# Automatically added by dh_apache2/UNDECLARED
+if [ "$1" = "remove" ] || [ "$1" = "deconfigure" ] ; then
+	if true; then
+		if [ -e /usr/share/apache2/apache2-maintscript-helper ] ; then
+			. /usr/share/apache2/apache2-maintscript-helper
+
+			for conf in multiflexi-doc  ; do
+				apache2_invoke disconf $conf  || exit 1
+			done
+		fi
+	fi
+fi
+# End automatically added section

debian/multiflexi-doc.substvars

@@ -1,2 +1,3 @@
+misc:Recommends=apache2 ( >= 2.4.6-4~ ) | httpd
 misc:Depends=
 misc:Pre-Depends=