Problem: Argument type mismatches are excluded from EmmyLua checks.

Solution: Correct runtime annotations and calls, document local checker
workarounds, and enable the diagnostic.

AI-assisted

Problem:
`parse_ssh_config()` compares tables against a freshly allocated empty
table.
- In `parse_multiple_values()`, the guard which avoids flushing an empty
  accumulator never applies. Runs of separators and trailing whitespace
  push empty strings into the results, and `is_valid()` does not filter
  them. `Host  alpha   beta ` parses as `{ 'alpha', '', 'beta' }`.
- In `parse_value()`, the condition reduces to `chr == '"' and quoted`.
  `quoted` starts false and only that branch sets it, so it can never
  become true: quotes are never recognised and are inserted literally,
  and the unterminated-quote check is unreachable.

Solution:
Compare `#val` instead. Add a test for repeated and trailing separators.

AI-assisted