Diacritic corrections, link styling, and a build lock

Eight diacritic corrections at seven sites, each verified against the page
image at 900 dpi:

  p0049  Nastaʿlīq -> Nasta`līq   the mark is a quote, not a ʿayn (Sammay)
  p0072  Cálidás   -> Cálidās
  p0256  Rajākṛṣṇa -> Rājākṛṣṇa
  p0260  Īsvaracandra -> Īśvaracandra  (x2)
  p0430  Iśvaracandra -> Īśvaracandra
  p0430  Gītā -> Gīta  (x2)
  p0430  Munṣī -> Munśī

Found by two nets over the transcription: a rare-character inventory
(U+02BF appeared exactly once in 431 pages — the tell) and a check for
names that appear with more than one accenting, 84 occurrences of which
~32 are now checked. Neither net catches a name mis-transcribed the SAME
way everywhere, so this is a partial sweep, not a clean bill.

The French accents are all handwritten additions in the scan — pen-drawn
cedillas and acutes — applied inconsistently by the author and reproduced
per instance. All of that cluster checks out.

Clickable regions now carry a 0.4pt hairline rule in RGB(95,125,165) on
the Contents/List-of-Plates page numbers and on resolved cross-references;
endnote superscripts and whole-line entries stay unmarked. polish.py emits
\xref for the former and \hyperlink for the latter so the two differ.

Also: plate 1's List-of-Plates entry uses \plx, which build_maps() did not
scan, so plate 1 was the one plate of 178 whose "pl. 1" references never
linked.

build.sh takes an atomic mkdir lock: two builds sharing work/ corrupt
main.aux and produce an error that names the wrong file entirely.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

tools/polish.py

@@ -31,6 +31,12 @@ def build_maps():
         t = open(f).read()
         for no, pg in re.findall(r"\\pl\{(\d+)\}\{.*?\}\{(\d+)\}", t):
             plate[int(no)] = int(pg)
+        # \plx is the one List-of-Plates entry whose location is not a bare page
+        # number (plate 1 is "page 18", a plate facing the text), so its page
+        # reference is wrapped in \pg. Without this, plate 1 was the single plate
+        # whose in-text "pl. 1" references never linked.
+        for no, pg in re.findall(r"\\plx\{(\d+)\}\{.*?\}\{.*?\\pg\{(\d+)\}", t):
+            plate[int(no)] = int(pg)
         for no, pg in re.findall(r"\\tocl\{[^}]*\}\{(\d+)\}\{.*?\}\{(\d+)\}", t):
             chap[int(no)] = int(pg)
         m = re.search(r"\\subchap\{(\d+)\.([ivx]+)", t)
@@ -43,13 +49,15 @@ def build_maps():
 PLATE, CHAP, SUBSEC = build_maps()
 
 def link(target, shown):
-    return r"\hyperlink{page.%d}{%s}" % (target, shown)
+    # \xref, not \hyperlink: the preamble gives \xref a visible hairline rule,
+    # while \hyperlink stays unmarked for the whole-line Contents and plate entries.
+    return r"\xref{page.%d}{%s}" % (target, shown)
 
 PROTECT = [
     re.compile(r"\\(?:erratum|qslip)\{[^}]*\}(?:\{[^}]*\})?"),
     re.compile(r"\\ig\{[^}]*\}"),
     re.compile(r"\\includegraphics(?:\[[^\]]*\])?\{[^}]*\}"),
-    re.compile(r"\\(?:origpage|fn|hyperlink|hypertarget|pg)\{[^}]*\}"),
+    re.compile(r"\\(?:origpage|fn|hyperlink|hypertarget|pg|xref)\{[^}]*\}"),
     re.compile(r"\\(?:plateop|plate)\{[^}]*\}\{[^}]*\}\{[^}]*\}"),
     re.compile(r"\\(?:pl|tocl|toclnp|erratumline)(?:\{[^}]*\})?"),
     # heading macros: their arguments become PDF bookmarks and running-head