Adding `--limit` To Canonry Runs CLI

With project run histories now exceeding 25 entries, the old canonry runs <project> command floods users with data - hard to parse, even harder to control. While PR #127 introduced strict validation for unknown flags, it exposed a clear gap: the absence of result limits. --limit <n> would let you cap output - like canonry runs ainyc --limit 5 - giving users back focus and bot efficiency. This fix mirrors patterns in google coverage-history, where pagination prevents overload. It’s not a feature overload - it’s a thoughtful response to growing digital fatigue. But here is the catch: the flag must reject arbitrary inputs and integrate cleanly with existing results, not just copy syntax. The real shift? Putting power in user hands, one run at a time - without drowning in endless history. Do you trust your CLI to respect your limits, or will you still sift through chaos?