Optimize and simplify loops, table lookups, and branchless parsers

- Replace sequential colon-counting loop with branchless CTZ bitmask in src/pen.h
- Replace linear strchr with 256-bit ASCII punctuation bitmask in src/selection.c
- Flatten 3D color cube loop and precompute constants in src/palette.c
- Use static 256-byte LUT for hex decoding and bsearch for termcap in src/escape.c
- Replace capacity doubling while loops with branchless CLZ pow2 helpers across core
- Use direct memset/memcpy in src/snapshot.c
- Optimize input digit/byte formatting, alt-prefix path, and make keyboard state optional in src/input.c

1 files changed, 1 insertions, 2 deletions

diff --git a/src/hist.c b/src/hist.c
index 123ed7b..bff1325 100644
--- a/src/hist.c
+++ b/src/hist.c
@@ -67,8 +67,7 @@ static TERM_NOINLINE bool ring_grow(struct hist *h, uint64_t n)
     uint64_t cap = h->ring ? (uint64_t)h->ring_mask + 1 : 65536;
     if (cap < 65536)
         cap = 65536;
-    while (cap < h->head - h->tail + n)
-        cap *= 2;
+    cap = term_grow_cap64(cap, h->head - h->tail + n);
     struct hline *ring = term_aligned_alloc(64, (size_t)cap * sizeof(*ring));
     if (!ring)
         return false;