Add BCE temporal tags to all documents; add temporal-dating steering doc

civilizations/ancient-egypt.md

@@ -4,32 +4,32 @@
 # Ancient Egypt
 
 ## Overview
-Ancient Egypt was a civilization centered along the Nile River in northeastern Africa, lasting from ~3100 BCE to 30 BCE. It produced monumental architecture, a complex writing system, and one of the longest-lasting state structures in history.
+Ancient Egypt was a civilization centered along the Nile River in northeastern Africa, lasting from ~3100 BCE to 30 BCE. It produced monumental architecture, a complex writing system, and one of the longest-lasting state structures in history. @t[~3100 BCE]
 
 ## Key Facts
 - Region: Nile Valley and Delta, northeastern Africa
-- Period: ~3100 BCE – 30 BCE (Roman annexation)
+- Period: ~3100 BCE – 30 BCE (Roman annexation) @t[3100 BCE..30 BCE]
 - Capital cities: Memphis, Thebes, Amarna, Alexandria (Ptolemaic)
 - Language: Egyptian (Afro-Asiatic family)
 - Writing systems: Hieroglyphic, Hieratic, Demotic
 - Religion: Polytheistic with pharaoh as divine intermediary
 
 ## Major Periods
-- Early Dynastic (~3100–2686 BCE): Unification under Narmer/Menes
-- Old Kingdom (~2686–2181 BCE): Pyramid age, centralized power
-- Middle Kingdom (~2055–1650 BCE): Cultural golden age
-- New Kingdom (~1550–1069 BCE): Imperial expansion, Ramesses II, Tutankhamun
-- Ptolemaic Period (305–30 BCE): Greek-ruled Egypt after Alexander's conquest
+- Early Dynastic (~3100–2686 BCE): Unification under Narmer/Menes @t[3100 BCE..2686 BCE]
+- Old Kingdom (~2686–2181 BCE): Pyramid age, centralized power @t[2686 BCE..2181 BCE]
+- Middle Kingdom (~2055–1650 BCE): Cultural golden age @t[2055 BCE..1650 BCE]
+- New Kingdom (~1550–1069 BCE): Imperial expansion, Ramesses II, Tutankhamun @t[1550 BCE..1069 BCE]
+- Ptolemaic Period (305–30 BCE): Greek-ruled Egypt after Alexander's conquest @t[305 BCE..30 BCE]
 
 ## Achievements
-- Great Pyramid of Giza, built ~2560 BCE under Khufu [^1]
-- Developed hieroglyphic writing ~3200 BCE
+- Great Pyramid of Giza, built ~2560 BCE under Khufu @t[~2560 BCE] [^1]
+- Developed hieroglyphic writing ~3200 BCE @t[~3200 BCE]
 - Advanced mummification and funerary practices
 - Sophisticated medicine, mathematics, and astronomy
 - Monumental temple complexes at Karnak and Luxor
 
 ## Decline
-Egypt fell under Persian rule (525 BCE), then Macedonian (332 BCE), and finally became a Roman province after the death of Cleopatra VII in 30 BCE.
+Egypt fell under Persian rule (525 BCE), then Macedonian (332 BCE), and finally became a Roman province after the death of Cleopatra VII in 30 BCE. @t[=525 BCE]
 
 ---
 [^1]: Lehner, M. *The Complete Pyramids* (Thames & Hudson, 1997)