v0.3.7 — lint knows a symbol is evidence

• wave lint now accepts a file name plus a named symbol in backticks (scripts/wave.py, cmd_cleanup) as evidence, not only file:line; yml/toml/json count for line refs. A lint that flags valid issues is noise the user learns to ignore.
• With this, all 16 leaves of epic #1 lint clean; /setwave:wave CarlosDanielDev/setwave#1 is ready to run.