Move git_tools, file_tools, and project_tools from libs/service into a
new libs/fctool crate with correct workspace dependencies. Fixes the
rev.len() >= 40 bug in all git tool resolve functions (OID check needs
exact 40-char hex, not just >= 40). Adds 4 new git blob tools
(blob_get, blob_exists, blob_content, blob_create). Fixes parameter
naming inconsistency in repos.rs and adds project_name to list_repos
output. Removes unused excel/pdf/ppt/word file tools.
