style(lang): British English compliance and AI-tell removal across learn content

[Bissbert]

Summary

Phase 2 of the gemmology.dev language sweep, targeting gemmology-knowledge content repo. Phase 1 (frontend) merged as PR #20.

• 84 files touched across all docs/learn/ directories
• 716 em-dashes replaced with Oxford-style spaced en-dashes (–); 26 residual "—" retained as null table-cell markers
• 1 AmE→BrE spelling swap: traveling → travelling (fundamentals/optical-properties.yaml)
• 3 AI-tell phrases removed:
  • pearl.yaml: "in today's market" → "available now" (+ fixed em-dash in same clause)
  • burma/ruby.yaml: "Burmese ruby in today's market:" → "Burmese ruby in the current market:"
  • east-africa/tsavorite.yaml: "Tsavorite in today's gem market:" → "Tsavorite in the current gem market:"
• 6 line-break fixes where em-dash → en-dash replacement produced a leading – at the start of a wrapped line (YAML-safe): twin-laws.yaml, ethiopia.yaml, montana-sapphire.yaml, russia/demantoid.yaml, thailand/ruby.yaml, thailand/overview.yaml

Em-dash before/after

Before	After	Notes
742	26	26 residual are legitimate "—" null table cells

AmE→BrE swaps

File	Change
fundamentals/optical-properties.yaml	traveling → travelling

AI-tell phrases removed

File	Phrase removed
species/pearl.yaml	"in today's market"
origin/burma/ruby.yaml	"in today's market"
origin/east-africa/tsavorite.yaml	"in today's gem market"

What was deliberately left unchanged

• All citation titles (e.g. "The Physics and Chemistry of Color", "Play-of-Color Opal"), author names, journal names — even where they contain AmE spellings
• All YAML keys — only values were edited
• All "—" used as null/empty table cell markers (26 instances in crystal-systems.yaml and other-tools.yaml)
• Chemical formulas, unit symbols, CDL code, URLs, DOIs, ISBNs

Verification gates

rg -- "—" docs/learn/ | wc -l    # → 26 (all legitimate null table cells)
rg -i "\b(color|behavior|organize|traveling|...)\b" docs/learn/ | grep -v citation/title  # → 0 hits
rg -i "\b(delve|seamless|in today's|...)\b" docs/learn/  # → 0 hits
python3 -c "import yaml,glob; [yaml.safe_load(open(f)) for f in glob.glob('docs/learn/**/*.yaml', recursive=True)]; print('YAML OK')"  # → YAML OK

Downstream

gemmology.dev picks up the cleaned YAML at next deploy via npm run sync — no downstream code change required.

🤖 Generated with Claude Code