[tools] (P7): the wire declines audit matches sites and logs on code alone, so a commented-out or quoted site is no site

Fable review of the B3 rework, must-fix: a row was "sited" by any line the
AT_SITE / COUNT_SITE regex matched, including a // comment, a /* */ block or
a string literal - `// MGL_WIRE_DECLINE_AT(GhostRow, "...");` satisfied the
audit for a row nothing counts, and an MGLOG_W inside a comment above a bare
Count() satisfied the log rule.

wire_declines_audit.py now blanks //...$ (with backslash-newline
continuation), /* ... */, "..." and '...' (raw strings R"d(...)d" and
C++14 digit separators handled) out of each source before any match. Every
character but the newline becomes a space, so the text keeps its length and
line count and each report still cites the real line.

Tree: 53 rows, 53 with sites, 53 sites, 0 unlogged, rc 0 (unchanged).
Fixtures that the previous audit passed and this one reds (rc 1): a
comment-only site (//), a comment-only site (/* */), a string-literal site,
a log only in a /* */ comment above a bare Count. The branch-blind window
and the .def trailing-comment row are the next commit.

scripts/ci/wire_declines_audit.py

@@ -17,6 +17,10 @@ Sites reached through MGL_WIRE_DECLINE_AT satisfy both at once. A bare
 WireDeclineTally::Count(WireDeclineSite::X) is allowed ONLY when an MGLOG_ statement carrying
 the same reason already stands just above it.
 
+Sources are matched on their text with comments and string/character literals blanked out
+(newlines kept, so every report cites the real line): a site or a log that is only a comment,
+or only a string, is not one.
+
 usage: wire_declines_audit.py [repo-root]
 """
 import os
@@ -35,6 +39,61 @@ COUNT_SITE = re.compile(r"WireDeclineTally::Count\(\s*WireDeclineSite::([A-Za-z]
 # Warning or error only: an MGLOG_D / MGLOG_V is compiled away in the Release builds that ship,
 # so it is not a line anybody can read off a device.
 LOGGED = re.compile(r"MGLOG_[WE](_ONCE)?\s*\(")
+RAW_PREFIX = re.compile(r"(?:^|[^A-Za-z0-9_])(?:u8|u|U|L)?R$")
+
+
+def strip_code(text: str) -> str:
+    """Blank out //, /* */ comments and string / character literals, keeping every newline.
+
+    What remains lines up with the source line for line, so a match's index is a real line
+    number. Raw strings R"d(...)d" and C++14 digit separators (1'000) are handled."""
+    out = list(text)
+    n = len(text)
+    i = 0
+
+    def blank(a: int, b: int) -> None:
+        for k in range(a, min(b, n)):
+            if out[k] != "\n":
+                out[k] = " "
+
+    while i < n:
+        c = text[i]
+        nxt = text[i + 1] if i + 1 < n else ""
+        if c == "/" and nxt == "/":
+            j = i
+            while j < n and text[j] != "\n":
+                # A backslash-newline continues a // comment onto the next line.
+                if text[j] == "\\" and j + 1 < n and text[j + 1] == "\n":
+                    j += 2
+                    continue
+                j += 1
+            blank(i, j)
+            i = j
+        elif c == "/" and nxt == "*":
+            j = text.find("*/", i + 2)
+            j = n if j < 0 else j + 2
+            blank(i, j)
+            i = j
+        elif c == '"' and RAW_PREFIX.search(text[max(0, i - 3):i]):
+            open_paren = text.find("(", i + 1)
+            if open_paren < 0:
+                blank(i, n)
+                break
+            delim = text[i + 1:open_paren]
+            close = text.find(")" + delim + '"', open_paren + 1)
+            j = n if close < 0 else close + len(delim) + 2
+            blank(i, j)
+            i = j
+        elif c == '"' or (c == "'" and not (i > 0 and (text[i - 1].isalnum() or text[i - 1] == "_"))):
+            j = i + 1
+            while j < n and text[j] != c and text[j] != "\n":
+                j += 2 if text[j] == "\\" else 1
+            j = min(j + 1, n)
+            blank(i, j)
+            i = j
+        else:
+            i += 1
+    return "".join(out)
 
 
 def main() -> int:
@@ -64,7 +123,8 @@ def main() -> int:
         if entry == "WireDeclineTally.h":
             continue
         path = os.path.join(src_dir, entry)
-        lines = open(path, encoding="utf-8", errors="replace").read().splitlines()
+        with open(path, encoding="utf-8", errors="replace") as f:
+            lines = strip_code(f.read()).splitlines()
         for i, line in enumerate(lines):
             for m in AT_SITE.finditer(line):
                 counted.setdefault(m.group(1), []).append((entry, i + 1))