If you backup a file that is large than the chunk size, the content array in the metadata does not contain a sha256 hash of the entire file, but rather of the chunks. So, no restic does not explicitly keep a hash of the entire file.
user@vm:/tmp/lol$ restic cat blob 3192cc4413266a3bd0d50c174eb6697df80d62e5f596f356d37c03a059fc5df4 -r .
enter password for repository:
repository 48f1f127 opened (version 2, compression level auto)
[0:00] 100.00% 2 / 2 index files loaded
{"nodes":[{"name":"abcdefg.zip","type":"file","mode":436,"mtime":"2025-01-19T19:39:15.417723715+01:00","atime":"2025-01-19T19:39:15.417723715+01:00","ctime":"2025-01-19T19:39:15.420723738+01:00","uid":1000,"gid":1000,"user":"user","group":"user","inode":45138072,"device_id":64513,"size":25491843,"links":1,"content":["23a713d00706ac7566d5167f15e6adf28728fae794e1efc9b0d3f42c43076e33","9975c511875c1d949456f2d9185e54c2bc69756a4adfc87b53f248565229a31b","7b76fbdc43fa34a44d75ce1756b5c4860019c5bdf3bb884aca9cdb71e1334950","3ae22f837c61f159d7ea7f5ea8d489828952ff2e8699cfe3d45e06dc3d37f42b","95832e4cabb117ebb0ed01c469023c235004f8a8854e50d5af1b1fa594770f74","224603c27307af6b7a4d0d7cf093fe3dc8f8b4d282d07239e345637c96238c2c","c9ab2f51c9cc29d02dfa74783323c2c642b5235340dfff1e4f64960856df4ac0","9207cf58a93207fe74c58bd1ba5cc3bc9ca71d74cf3b6ddf266597c4804f3fe2","39e7ddcff21642ea8106251553cce56f032e577aec6b50600ac63d7e49115ad0","aa1a362d481362cd9fd62647d9e891b8d85efae809987ff6376403fe0906091f","e66abaa112dcf24125950a8fdb5d16607bd2d6b18764a87a0d8bbf8709c86f52","32ad0837084ed39a7e8e256f76362bfe7b2bd3e55b32c629e30768e8e11b0f18","3d7f83c5be24db0b5c340700d7a940ffddbaa8d2cd06960f2d80b6b38585f86c","5333439f8438d362a533c92eccd5f9f608b47ac9d96fa9b05e230f92a44376d5","a546e371dac985cfcee413900649d8dc59781983e680e86747459b1e386324d8","dd8ea4638a2ec10958dd65a8e88a305b8a4c95cc53f2690be2a386cdd165c8e6","c26df9e4daf12b3ab3e3e12d245fa64ff2a0b27e2398598a74c81ed3cdc17f2a","658aed5b3cb569f7e14e91191e55022d1598d5df80564ac43791c9c6f25c78f3","6db0cb45b6108e713c18ae4560cde5e5160d950bffd600a722656463d8523dd5","ba1f82786a2df46bb15b464baa97f8e3cbc0210ea61d5b8f1277bb35b51bf43c","9aa71ad8c163a3c75e87562711760508d2e31200202ff349a7f3f1c7193e2298","f7382af93571bf9f4e4ed32b0301f6eebca15ef847e44f0bfaed8ca3512bbccc"]}]}