docs: add AGENTS.md with guidelines for code contributions

AGENTS.md

@@ -0,0 +1,70 @@
+# Purefin AGENTS.md
+
+Follow these instructions before making changes:
+
+* Understand the relevant files before editing.
+* Always follow official Android recommendations and best practices.
+* Always include the pages you have read in your reply, even in planning mode.
+* Prefer small, targeted changes over broad refactors.
+* Preserve existing architecture and naming unless the task requires a change.
+* Do not introduce new dependencies without a clear reason.
+* Ask for clarification or leave a note when requirements are ambiguous.
+
+---
+
+## Repository Expectations
+
+* Always use the currently used syntax in the codebase. Include examples for any naming you introduce.
+* Avoid touching unrelated files.
+* Do not fix unrelated existing problems in the codebase.
+* Prefer consistency with the existing codebase over idealized patterns.
+* When modifying a file, match its local style and conventions.
+* Favor readable, maintainable code over clever code.
+
+---
+
+## Testing
+
+* Running a build is sufficient to verify your implementation.
+* Do not write tests unless explicitly asked to.
+
+---
+
+## Git and Commit Rules
+
+When asked to prepare a commit:
+
+* Use **Conventional Commits** format.
+* Format:
+
+  ```
+  <type>(<scope>): <description>
+  ```
+* The description should not be too long, but must include any major change.
+* Use imperative mood.
+* Keep the subject concise.
+
+**Common types:**
+
+* `feat` – new feature
+* `fix` – bug fix
+* `refactor` – code change without feature or fix
+* `test` – adding or updating tests
+* `docs` – documentation changes
+* `chore` – maintenance tasks
+* `build` – build system changes
+* `ci` – CI/CD changes
+
+---
+
+## Preferred Workflow
+
+1. Read the task carefully.
+2. Read relevant official Google/Android documentation.
+3. Inspect the relevant files and nearby code.
+4. Choose the simplest solution aligned with Google’s standards.
+5. Check if the code can be simplified:
+
+   * If yes, simplify it.
+   * Do not reduce readability.
+6. Summarize the result, including anything not verified.