feat: add global AGENTS.md

Author: yeskunall

.config/opencode/AGENTS.md

@@ -0,0 +1,93 @@
+## Purpose
+
+This document defines baseline conventions and expectations for all agents
+contributing to any project. Treat this as a living document -- expect things
+to change with time. Use this doc as a starting point, but do not treat it as
+the single source of truth.
+
+## General guidelines
+
+- **Complexity is your arch-nemesis**. Write clear, maintainable, and minimal
+  code. Avoid unnecessary abstractions. You’re writing code for humans first,
+  computers second.
+- Saying no (to a feature or abstraction or rewrite) is OK.
+- Sometimes you have no choice but to say OK because otherwise it halts all
+  progress.
+- **Easier to ask for permission than to repair the damage**. Unless you are
+  explicitly given permission, always ask before committing to something.
+- **Always favor being explicit over implicit**.
+- **Follow the principle of least surprise** -- your code should behave in a
+  way that most users will expect it to behave, and therefore not astonish or
+  surprise users.
+- Default to idempotent operations and stateless design when possible.
+- **Avoid premature optimization**.
+- Always program defensively (more under #security-considerations).
+- **Treat warnings and errors as bugs to fix, not noise to ignore.**
+- Always use `context7` tools when you need code generation, setup or
+  configuration steps, or documentation. Automatically use the Context7 MCP
+  tools to resolve the `libraryId` and get library docs without me having to
+  explicitly ask.
+- If you are unsure how to do something, use `gh_grep` to search code examples
+  from GitHub.
+
+## Writing good commit messages
+
+Follow the [Conventional Commits](https://www.conventionalcommits.org/en/v1.0.0/#specification)
+spec when writing commit messages, unless a project defines its own guidelines.
+
+Additionally:
+
+- Description should be concise and in the imperative mood (e.g. “add”, not
+  “adds” or “added”).
+- Only use lowercase for the commit summary.
+- No period at the end of the commit summary.
+- The commit summary should not exceed 75 characters (if at all possible).
+- You can write a longer commit body in addition to the
+
+### Examples
+
+#### Commit message with no body
+
+```
+docs: correct spelling of CHANGELOG
+```
+
+#### Commit message with scope
+
+```
+feat(lang): add Polish language
+```
+
+#### Commit message with multi-paragraph body and multiple footers
+
+```
+fix: prevent racing of requests
+
+Introduce a request id and a reference to latest request. Dismiss
+incoming responses other than from latest request.
+
+Remove timeouts which were used to mitigate the racing issue but are
+obsolete now.
+
+Reviewed-by: Z
+Refs: #123
+```
+
+## Security considerations
+
+- **Never** log sensitive data (credentials, PII, secrets).
+- Do **not** install any new dependencies if the task can be achieved using
+  existing libraries (standard lib or existing dependencies).
+- You must assume that your code might be misused actively to reveal bugs,
+  and that bugs could be exploited maliciously.
+- If data is to be checked for correctness, verify that it is correct, not that
+  it is incorrect.
+- Use assertions if the programming language (or runtime) supports them.
+- **All data is important until proven otherwise** -- all data must be verified
+  as garbage before being destroyed.
+- **All data is tainted until proven otherwise** -- all data must be handled in
+  a way that does not expose the rest of the runtime environment without
+  verifying integrity.
+- **All code is insecure until proven otherwise** -- never assume your code is
+  secure as bugs or undefined behavior may expose the project or system to
+  attacks such as common SQL injection attacks.