docs: add community governance and contribution guidelines

- Add CONTRIBUTING.md with TDD requirements, PR workflow, and AI usage
  policy
- Add CODE_OF_CONDUCT.md based on Contributor Covenant
- Add SECURITY.md with vulnerability reporting scope and process
- Add AGENTS.md with AI usage policy for human contributors and AI
  agents
- Add CLAUDE.md to require reading AGENTS.md before any work
- Add Gitea issue templates for bug reports and feature requests
- Add pull request template with TDD and code quality checklist

.gitea/ISSUE_TEMPLATE/BUG-REPORT.yml

@@ -0,0 +1,97 @@
+name: Bug Report
+description: File a bug report
+title: "[Bug]: "
+labels: ["bug/unconfirmed"]
+body:
+  - type: markdown
+    attributes:
+      value: |
+        Thanks for taking the time to fill out this bug report!
+  - type: textarea
+    id: expected-behaviour
+    attributes:
+      label: Expected behaviour
+      description: How do you expect STA to behave?
+      placeholder: "Relay 3 should turn on after calling POST /api/relays/3/toggle"
+    validations:
+      required: true
+  - type: textarea
+    id: what-happened
+    attributes:
+      label: Actual behaviour
+      description: How does the actual behaviour differ from the expected behaviour?
+      placeholder: "The relay state remains unchanged and the API returns a 500 error"
+    validations:
+      required: true
+  - type: textarea
+    id: reproduction-steps
+    attributes:
+      label: Steps to reproduce
+      description: Step-by-step instructions to reproduce the issue reliably
+      placeholder: |
+        1. Start the STA backend with the following configuration: ...
+        2. Send a POST request to /api/relays/3/toggle
+        3. Observe that ...
+    validations:
+      required: true
+  - type: dropdown
+    id: component
+    attributes:
+      label: Affected component
+      description: Which part of STA is affected?
+      options:
+        - Backend API
+        - Frontend
+        - Modbus hardware communication
+        - Configuration
+        - Other / unsure
+    validations:
+      required: true
+  - type: dropdown
+    id: package-version
+    attributes:
+      label: STA version
+      description: What version of STA are you using?
+      options:
+        - main
+        - develop
+        - something else (please specify)
+  - type: dropdown
+    id: source
+    attributes:
+      label: Source of backend
+      description: From which source did you get the backend?
+      options:
+        - Compiled yourself (Nix development shell)
+        - Compiled yourself (non-Nix development shell)
+        - Release binary
+        - Docker image
+        - something else (please specify)
+  - type: dropdown
+    id: os-platform
+    attributes:
+      label: Operating system and platform
+      description: On which OS and hardware are you running the STA backend?
+      options:
+        - Linux (ARM / Raspberry Pi)
+        - Linux (x86_64)
+        - Other (please specify)
+    validations:
+      required: true
+  - type: textarea
+    id: rust-version
+    attributes:
+      label: Rust version
+      description: If you compiled the binary yourself, which version of Rust did you use?
+      placeholder: "Rust 1.y.z"
+  - type: textarea
+    id: logs
+    attributes:
+      label: Relevant code or log output
+      description: Please copy and paste any relevant code or log output. This will be automatically formatted into code, so no need for backticks.
+      render: text
+  - type: textarea
+    id: other-info
+    attributes:
+      label: Other relevant information
+      description: Please provide any other information which could be relevant to the issue (SQLite version? Upstream bug?)

.gitea/ISSUE_TEMPLATE/DOCUMENTATION-ISSUE.yml

@@ -0,0 +1,59 @@
+name: Documentation Issue
+description: Report missing, incorrect, or unclear documentation
+title: "[Docs]: "
+labels: ["documentation"]
+body:
+  - type: markdown
+    attributes:
+      value: |
+        Use this template to report issues in the documentation, such as missing
+        content, incorrect information, or unclear explanations.
+  - type: dropdown
+    id: doc-location
+    attributes:
+      label: Documentation location
+      description: Which part of the documentation is affected?
+      options:
+        - README
+        - CONTRIBUTING.md
+        - Wiki
+        - rustdoc (inline code documentation)
+        - API documentation (OpenAPI / Swagger UI)
+        - specs/ (specifications and constitution)
+        - docs/ (guides)
+        - Other
+    validations:
+      required: true
+  - type: input
+    id: doc-page
+    attributes:
+      label: Specific page or section
+      description: Link or name of the specific page, section, or function affected
+      placeholder: "e.g. docs/cors-configuration.md § Fail-Safe Defaults"
+  - type: dropdown
+    id: issue-type
+    attributes:
+      label: Type of issue
+      options:
+        - Missing documentation (undocumented feature or behaviour)
+        - Incorrect information
+        - Outdated information
+        - Unclear or confusing explanation
+        - Broken link
+        - Other
+    validations:
+      required: true
+  - type: textarea
+    id: description
+    attributes:
+      label: Description
+      description: Describe the documentation issue in detail
+      placeholder: "The section on X does not explain Y, which is needed to Z..."
+    validations:
+      required: true
+  - type: textarea
+    id: suggested-fix
+    attributes:
+      label: Suggested improvement
+      description: If you have a suggestion for how to fix or improve the documentation, please share it
+      placeholder: "The section should clarify that..."

.gitea/ISSUE_TEMPLATE/FEATURE-REQUEST.yml

@@ -0,0 +1,40 @@
+name: Feature Request
+description: Request a new feature
+title: "[Feature Request]: "
+labels: ["enhancement"]
+body:
+  - type: markdown
+    attributes:
+      value: |
+        Thanks for taking the time to request a new feature!
+  - type: checkboxes
+    id: pre-submission
+    attributes:
+      label: Pre-submission checklist
+      options:
+        - label: I have searched existing issues and this feature has not already been requested
+          required: true
+  - type: textarea
+    id: feature-description
+    attributes:
+      label: New feature
+      description: Description of the new feature
+      placeholder: "Describe the feature you would like to see added to STA"
+    validations:
+      required: true
+  - type: textarea
+    id: feature-reason
+    attributes:
+      label: Why this new feature
+      description: Describe why this new feature should be added to STA
+      placeholder: "Describe the problem this feature would solve or the value it would add"
+    validations:
+      required: true
+  - type: textarea
+    id: ideas-implementation
+    attributes:
+      label: Implementation ideas and additional thoughts
+      description: Do you have an idea on how to implement it?
+      placeholder: "It could be implemented by..."
+    validations:
+      required: false

.gitea/ISSUE_TEMPLATE/HARDWARE-COMPATIBILITY.yml

@@ -0,0 +1,73 @@
+name: Hardware Compatibility Report
+description: Report compatibility issues with a specific Modbus relay device
+title: "[Hardware]: "
+labels: ["hardware", "compatibility"]
+body:
+  - type: markdown
+    attributes:
+      value: |
+        Use this template to report issues specific to a Modbus relay device that STA
+        fails to communicate with or control correctly.
+  - type: textarea
+    id: device-info
+    attributes:
+      label: Device information
+      description: Manufacturer, model, and firmware version of the relay device
+      placeholder: |
+        Manufacturer: ...
+        Model: ...
+        Firmware: ...
+    validations:
+      required: true
+  - type: textarea
+    id: modbus-config
+    attributes:
+      label: Modbus configuration
+      description: The Modbus settings you are using (from your base.yaml or environment variables)
+      placeholder: |
+        host: 192.168.x.x
+        port: 502
+        slave_id: x
+        timeout_secs: x
+    validations:
+      required: true
+  - type: textarea
+    id: expected-behaviour
+    attributes:
+      label: Expected behaviour
+      description: What should STA be able to do with this device?
+      placeholder: "STA should be able to read and toggle all 8 relays"
+    validations:
+      required: true
+  - type: textarea
+    id: actual-behaviour
+    attributes:
+      label: Actual behaviour
+      description: What does STA actually do?
+      placeholder: "STA returns a Modbus exception or times out when writing a coil"
+    validations:
+      required: true
+  - type: textarea
+    id: logs
+    attributes:
+      label: Relevant log output
+      description: Please paste any relevant STA log output. This will be formatted as code automatically.
+      render: text
+    validations:
+      required: true
+  - type: dropdown
+    id: os-platform
+    attributes:
+      label: Operating system and platform
+      description: On which OS and hardware are you running the STA backend?
+      options:
+        - Linux (ARM / Raspberry Pi)
+        - Linux (x86_64)
+        - Other (please specify)
+    validations:
+      required: true
+  - type: textarea
+    id: additional-info
+    attributes:
+      label: Additional information
+      description: Any other context that may help, such as Modbus traffic captures, wiring details, or links to the device datasheet