fix: TOKEN_SAVIOR_MAX_FILES env var had no effect

[mazulo]

Summary

• max_files defaulted to 10_000 in ProjectIndexer.__init__, so self.max_files = max_files or int(os.environ.get("TOKEN_SAVIOR_MAX_FILES", "10000")) always short-circuited — env var was never read
• Same issue for max_file_size_bytes / TOKEN_SAVIOR_MAX_FILE_SIZE
• Fixed both by changing defaults to None so the or falls through when no explicit value is passed
• Added two tests covering both env vars

[andrebrait]

I think this is already covered by #54?

[mazulo]

I think this is already covered by #54?

@andrebrait dang, you're right! Sorry my bad, I swear I did look at the PRs but didn't see yours :lolsob:

I'll close this one, let's get yours merged!