Adds stable CodSpeed baselines for public construction and execution paths across byte length, binary arithmetic, LIKE, tensor scalar functions, and geo operations. The benches avoid RowFn test-harness internals so later implementation changes compare against the production path.

`like_per_row_patterns` keeps its original repeated `hello%` fixture so its CodSpeed history stays comparable. The compile-cache pair lands under new names: `like_per_row_repeated_patterns` and `like_per_row_distinct_patterns` share a five-byte pattern shape and differ only in whether the cache hits.

Geo distance covers point and polygon columns, including constants and nullable points. Geo predicate coverage adds sparse and mixed validity cases, while its all-overlapping polygon arm uses 1,024 rows because CodSpeed simulates the compiled amd64/AVX2 machine code.

Each benchmark binary that allocates inside the timed region uses vendored `mimalloc`. `Normalized` keeps its checked inherent constructor because its normalized-row invariant requires construction-time validation.

Signed-off-by: Connor Tsui <connor.tsui20@gmail.com>