fix(narrow): byte 缓冲写 32 位掩码结果改用 uint8(...)

base64 解码输出、zipfile zf_w16le/zf_win32le、zlib adler/gzip 尾写：目标为 bytes/uint8*/BYTE*（8 位），RHS 为 32 位表达式，触发隐式窄化；统一加 uint8(...)

base64.vp

@@ -64,12 +64,12 @@ def b64decode(s: str, out: uint8*) -> sizet:
         c = s[i+3] - 43
         if s[i+3] != '=': val |= (b64_dec_tab[c] & 0x3F)
         # Write recovered bytes
-        out[j] = (val >> 16) & 0xFF
+        out[j] = uint8((val >> 16) & 0xFF)
         j += 1
         if s[i+2] != '=':
-            out[j] = (val >> 8) & 0xFF
+            out[j] = uint8((val >> 8) & 0xFF)
             j += 1
         if s[i+3] != '=':
-            out[j] = val & 0xFF
+            out[j] = uint8(val & 0xFF)
             j += 1
     return j

zipfile.vp

@@ -114,15 +114,15 @@ def zf_u32le(p: uint8*) -> uint32:
 
 
 def zf_w16le(h: uint8*, v: uint32):
-    h[0] = v & 0xFF
-    h[1] = (v >> 8) & 0xFF
+    h[0] = uint8(v & 0xFF)
+    h[1] = uint8((v >> 8) & 0xFF)
 
 
 def zf_win32le(h: uint8*, v: uint32):
-    h[0] = v & 0xFF
-    h[1] = (v >> 8) & 0xFF
-    h[2] = (v >> 16) & 0xFF
-    h[3] = (v >> 24) & 0xFF
+    h[0] = uint8(v & 0xFF)
+    h[1] = uint8((v >> 8) & 0xFF)
+    h[2] = uint8((v >> 16) & 0xFF)
+    h[3] = uint8((v >> 24) & 0xFF)
 
 
 # All file openings allow read/write/delete sharing, avoiding mutually exclusive handles

zlib/pyzlib.vp

@@ -159,10 +159,10 @@ class Compress:
             if s.wbits >= 0:
                 s.writer.align()
                 adler: uint32 = s.adler
-                s.writer.buf[s.writer.byte_pos + 0] = (adler >> 24) & 0xFF
-                s.writer.buf[s.writer.byte_pos + 1] = (adler >> 16) & 0xFF
-                s.writer.buf[s.writer.byte_pos + 2] = (adler >>  8) & 0xFF
-                s.writer.buf[s.writer.byte_pos + 3] = (adler >>  0) & 0xFF
+                s.writer.buf[s.writer.byte_pos + 0] = uint8((adler >> 24) & 0xFF)
+                s.writer.buf[s.writer.byte_pos + 1] = uint8((adler >> 16) & 0xFF)
+                s.writer.buf[s.writer.byte_pos + 2] = uint8((adler >>  8) & 0xFF)
+                s.writer.buf[s.writer.byte_pos + 3] = uint8((adler >>  0) & 0xFF)
                 s.writer.byte_pos += 4
             self.is_finished = 1
             total: sizet = s.writer.total()
@@ -590,14 +590,14 @@ def compress(pool: memhub.MemManager*, data: BYTEPTR, data_len: sizet,
             pool.free(raw_result)
 
         crc: uint32 = zchecksum.zchecksum_crc32(data, data_len, 0)
-        gzip_buf[pos + 0] = (crc) & 0xFF
-        gzip_buf[pos + 1] = (crc >> 8) & 0xFF
-        gzip_buf[pos + 2] = (crc >> 16) & 0xFF
-        gzip_buf[pos + 3] = (crc >> 24) & 0xFF
-        gzip_buf[pos + 4] = (data_len) & 0xFF
-        gzip_buf[pos + 5] = (data_len >> 8) & 0xFF
-        gzip_buf[pos + 6] = (data_len >> 16) & 0xFF
-        gzip_buf[pos + 7] = (data_len >> 24) & 0xFF
+        gzip_buf[pos + 0] = uint8((crc) & 0xFF)
+        gzip_buf[pos + 1] = uint8((crc >> 8) & 0xFF)
+        gzip_buf[pos + 2] = uint8((crc >> 16) & 0xFF)
+        gzip_buf[pos + 3] = uint8((crc >> 24) & 0xFF)
+        gzip_buf[pos + 4] = uint8((data_len) & 0xFF)
+        gzip_buf[pos + 5] = uint8((data_len >> 8) & 0xFF)
+        gzip_buf[pos + 6] = uint8((data_len >> 16) & 0xFF)
+        gzip_buf[pos + 7] = uint8((data_len >> 24) & 0xFF)
         pos += 8
         *out_len = pos
         return shrink_to_fit(pool, gzip_buf, pos)

zlib/zdeflate.vp

@@ -199,10 +199,10 @@ class zdeflate_stream:
             if self.wbits >= 0:
                 self.writer.align()
                 adler: uint32 = self.adler
-                self.writer.buf[self.writer.byte_pos + 0] = (adler >> 24) & 0xFF
-                self.writer.buf[self.writer.byte_pos + 1] = (adler >> 16) & 0xFF
-                self.writer.buf[self.writer.byte_pos + 2] = (adler >>  8) & 0xFF
-                self.writer.buf[self.writer.byte_pos + 3] = (adler >>  0) & 0xFF
+                self.writer.buf[self.writer.byte_pos + 0] = uint8((adler >> 24) & 0xFF)
+                self.writer.buf[self.writer.byte_pos + 1] = uint8((adler >> 16) & 0xFF)
+                self.writer.buf[self.writer.byte_pos + 2] = uint8((adler >>  8) & 0xFF)
+                self.writer.buf[self.writer.byte_pos + 3] = uint8((adler >>  0) & 0xFF)
                 self.writer.byte_pos += 4
         elif mode == 2 or mode == 3:
             self.writer.write_bits(0, 1)
@@ -426,10 +426,10 @@ def zdeflate_one_shot(pool: memhub.MemManager*, data: UINT8PTR, length: sizet,
     if wbits >= 0:
         s.writer.align()
         adler: uint32 = s.adler
-        s.writer.buf[s.writer.byte_pos + 0] = (adler >> 24) & 0xFF
-        s.writer.buf[s.writer.byte_pos + 1] = (adler >> 16) & 0xFF
-        s.writer.buf[s.writer.byte_pos + 2] = (adler >>  8) & 0xFF
-        s.writer.buf[s.writer.byte_pos + 3] = (adler >>  0) & 0xFF
+        s.writer.buf[s.writer.byte_pos + 0] = uint8((adler >> 24) & 0xFF)
+        s.writer.buf[s.writer.byte_pos + 1] = uint8((adler >> 16) & 0xFF)
+        s.writer.buf[s.writer.byte_pos + 2] = uint8((adler >>  8) & 0xFF)
+        s.writer.buf[s.writer.byte_pos + 3] = uint8((adler >>  0) & 0xFF)
         s.writer.byte_pos += 4
     *out_len = s.writer.total()
     result: UINT8PTR = UINT8PTR(zdef.zdef_alloc(pool, *out_len))