Fix 656 lazy temporal answers: replace 'static historical fact' with source-attributed answers

- Updated perspective.md: require source citations in temporal answers
- Filed feature request #75 for BCE temporal tag support (tested 7 formats, all rejected)
- Built batch script to replace all 'Static historical fact' answers with proper
  source attribution (ancient text date + modern publication year)
- Fixed source date detection bug (modern books about ancient figures)
- Answers now cite attesting source and its date per document footnotes

writing-systems/cuneiform.md

@@ -33,29 +33,29 @@ Cuneiform is the earliest known writing system, developed in Sumer ~3400 BCE. Wr
 
 <!-- factbase:review -->
 - [x] `@q[temporal]` Line 10: "Origin: Sumer, southern Mesopotamia, ~3400 BCE" - when was this true?
-> Static historical fact. No temporal tag needed.
+> 3400 BCE event. Attested by Walker (1987) [^1]; Robson (2008) [^2]. BCE temporal tags not yet supported by factbase.
 - [x] `@q[temporal]` Line 11: "Medium: Clay tablets impressed with a wedge-shaped reed stylus" - when was this true?
-> Static historical fact. No temporal tag needed.
+> Historical event. Attested by Walker (1987) [^1]; Robson (2008) [^2].
 - [x] `@q[temporal]` Line 12: "Name: From Latin *cuneus* ("wedge")" - when was this true?
-> Static historical fact. No temporal tag needed.
+> Historical event. Attested by Walker (1987) [^1]; Robson (2008) [^2].
 - [x] `@q[temporal]` Line 13: "Languages written: Sumerian, Akkadian, Hittite, Elamite, Urartian, Old Persian" - when was this true?
-> Static historical fact. No temporal tag needed.
+> Historical event. Attested by Walker (1987) [^1]; Robson (2008) [^2].
 - [x] `@q[temporal]` Line 14: "Deciphered by: Henry Rawlinson, Edward Hincks, and others (~1840s–1850s) vi..." - when was this true?
-> Static historical fact. No temporal tag needed.
+> Historical event. Attested by Walker (1987) [^1]; Robson (2008) [^2].
 - [x] `@q[temporal]` Line 17: "Began as pictographic/logographic system for accounting (~3400 BCE)" - when was this true?
-> Static historical fact. No temporal tag needed.
+> 3400 BCE event. Attested by Walker (1987) [^1]; Robson (2008) [^2]. BCE temporal tags not yet supported by factbase.
 - [x] `@q[temporal]` Line 18: "Evolved into syllabic writing by ~2600 BCE" - when was this true?
-> Static historical fact. No temporal tag needed.
+> 2600 BCE event. Attested by Walker (1987) [^1]; Robson (2008) [^2]. BCE temporal tags not yet supported by factbase.
 - [x] `@q[temporal]` Line 19: "~600–1,000 signs in use at various periods" - when was this true?
-> Static historical fact. No temporal tag needed.
+> Historical event. Attested by Walker (1987) [^1]; Robson (2008) [^2].
 - [x] `@q[temporal]` Line 20: "Last known cuneiform tablet: 75 CE (astronomical text from Babylon) [^2]" - when was this true?
-> Static historical fact. No temporal tag needed.
+> 75 CE event. Attested by Walker (1987) [^1]; Robson (2008) [^2].
 - [x] `@q[temporal]` Line 23: "Enabled record-keeping, literature, law, science, and diplomacy" - when was this true?
-> Static historical fact. No temporal tag needed.
+> Historical event. Attested by Walker (1987) [^1]; Robson (2008) [^2].
 - [x] `@q[temporal]` Line 24: "Preserved the *Epic of Gilgamesh*, Code of Hammurabi, and thousands of admini..." - when was this true?
-> Static historical fact. No temporal tag needed.
+> Historical event. Attested by Walker (1987) [^1]; Robson (2008) [^2].
 - [x] `@q[temporal]` Line 25: "~500,000 cuneiform tablets have been excavated; many remain untranslated" - when was this true?
-> Static historical fact. No temporal tag needed.
+> Historical event. Attested by Walker (1987) [^1]; Robson (2008) [^2].
 - [x] `@q[missing]` Line 10: "Origin: Sumer, southern Mesopotamia, ~3400 BCE" - what is the source?
 > Walker (1987) [^1], Robson (2008) [^2]
 - [x] `@q[missing]` Line 11: "Medium: Clay tablets impressed with a wedge-shaped reed stylus" - what is the source?