docs(aidd-context): apply concise reading and writing guidance

[alexsoyes]

🎯 What & why

Apply concise reading and writing guidance to chat, documents, and code comments. The previous rule focused on chat.

🧪 How to verify

• Independent review approved both replacements; required context, facts, constraints, and nuance remain covered.
• git diff --check and commit hooks pass.
• Push hooks pass: CLI knip and 6,795 tests (one skipped), using an isolated Node directory for the test sandbox.

✅ I certify

• I DO CERTIFY I READ EACH LINE OF THE PULL REQUEST BECAUSE I AM A SOFTWARE ENGINEER, NOT A AI PUPPY.