New default empty state

[z-tofu]

The Problem

Currently, if a user explicitly passes ?num=0 (or 00, which happened to me when building a clock that hit the top of the minute/hour), the counter ignores the override and acts as a standard page-hit counter instead.

This happens because the Zod schema defaults to 0, the route destructuring defaults to 0, and the getCountByName function explicitly checks if (num > 0) to bypass the database. Because 0 is not greater than 0, it falls through to the database increment logic.

The Solution

This PR introduces -1 as the new default "empty" state, allowing the backend to differentiate between "the user didn't provide a number" and "the user explicitly wants to display zero."

Changes Made:

• Zod Schema: Lowered the min constraint of num to -1 and updated the default to -1.
• Route Destructuring: Updated the fallback value of num from 0 to -1 in the app.get route.
• Function Logic: Updated the manual override check in getCountByName from if (num > 0) to if (num >= 0).

Testing & Impact

• Backwards Compatible: Yes. Standard hit-counter requests (where num is omitted) will now default to -1. Since -1 is not >= 0, they will safely fall through to the standard database increment logic just like before.
• Fixes: Users can now successfully render the 0 or 00 images by passing ?num=0.