fix(store.c): improve root path integrity check with range-based validation

[noctrex]

Replace the NOT IN list of individual characters with a range-based BETWEEN 'A' AND 'Z' check for validating project root paths.
The previous query only excluded letters A–H, leaving paths starting with I–Z silently invalid.
In Windows, all the alphabet can be used.
A Windows drive starting with letters I-Z breaks the saving of the database.

[DeusData]

Merged via rebase, thanks @noctrex. Good catch — the original 'A','B','C','D','E','F','G','H' enumeration was clearly intended to cover Windows drive letters but stopped at H, so any project rooted on I: through Z: was getting flagged as integrity-violating. The BETWEEN 'A' AND 'Z' rewrite is the right shape for the check.

One follow-up worth knowing about (not blocking, won't change here): the integrity check still only accepts uppercase drive letters. If cbm_project_name_from_path or any caller upstream ever stores a path like c:\foo (lowercase), the check would re-flag it. Most Windows tooling normalizes drive letters to uppercase so this is unlikely to bite, but if it does, extending to BETWEEN 'A' AND 'z' (or two ranges) is the obvious next step. Not in scope for this PR.

Closes the same diagnosis from #309. Nice contribution.

[noctrex]

Merged via rebase, thanks @noctrex. Good catch — the original 'A','B','C','D','E','F','G','H' enumeration was clearly intended to cover Windows drive letters but stopped at H, so any project rooted on I: through Z: was getting flagged as integrity-violating. The BETWEEN 'A' AND 'Z' rewrite is the right shape for the check.

One follow-up worth knowing about (not blocking, won't change here): the integrity check still only accepts uppercase drive letters. If cbm_project_name_from_path or any caller upstream ever stores a path like c:\foo (lowercase), the check would re-flag it. Most Windows tooling normalizes drive letters to uppercase so this is unlikely to bite, but if it does, extending to BETWEEN 'A' AND 'z' (or two ranges) is the obvious next step. Not in scope for this PR.

Closes the same diagnosis from #309. Nice contribution.

I only catched this because I have a drive called R:, and it was failing for this specific drive :)
It won't be a problem because on Windows the path & file names are case-insensitive by default.