274: vendor the transect page into the repo

Keeps the interactive map available offline and under version control
while the song is in progress.

- 274-transect.html — self-contained; carries its data in a script block,
  fonts from Google Fonts, no other external requests. Opens by double
  clicking. Same page as the published artifact.
- 274-route.json, 274-districts.json — the route line and the 23 大字
  bands from the 250 m reverse-geocode sweep.
- 274-transect-build.py — re-reads the roster out of 274-dev.md and
  rewrites the page's data block in place, leaving markup and script
  alone. Run it after editing the table.

Everything under wip/ so the auto-wiki pipeline leaves it alone.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01S6MpcBisZYhX45oDGRRJoz

wip/274-districts.json

@@ -0,0 +1,186 @@
+[
+ {
+  "frm": 36.5,
+  "to": 38.25,
+  "code": "01427",
+  "city": "夕張郡由仁町",
+  "lv": "川端",
+  "kana": "かわばた"
+ },
+ {
+  "frm": 38.5,
+  "to": 42.0,
+  "code": "01429",
+  "city": "夕張郡栗山町",
+  "lv": "字滝下",
+  "kana": "たきした"
+ },
+ {
+  "frm": 42.25,
+  "to": 43.0,
+  "code": "01427",
+  "city": "夕張郡由仁町",
+  "lv": "川端",
+  "kana": "かわばた"
+ },
+ {
+  "frm": 43.25,
+  "to": 44.0,
+  "code": "01429",
+  "city": "夕張郡栗山町",
+  "lv": "字滝下",
+  "kana": "たきした"
+ },
+ {
+  "frm": 44.25,
+  "to": 48.25,
+  "code": "01209",
+  "city": "夕張市",
+  "lv": "滝ノ上",
+  "kana": "たきのうえ"
+ },
+ {
+  "frm": 48.5,
+  "to": 55.5,
+  "code": "01209",
+  "city": "夕張市",
+  "lv": "紅葉山",
+  "kana": "もみじやま"
+ },
+ {
+  "frm": 55.75,
+  "to": 57.75,
+  "code": "01209",
+  "city": "夕張市",
+  "lv": "楓",
+  "kana": "かえで"
+ },
+ {
+  "frm": 58.0,
+  "to": 61.0,
+  "code": "01209",
+  "city": "夕張市",
+  "lv": "登川",
+  "kana": "のぼりかわ"
+ },
+ {
+  "frm": 61.25,
+  "to": 62.75,
+  "code": "01586",
+  "city": "勇払郡むかわ町",
+  "lv": "穂別長和",
+  "kana": "ほべつおさわ"
+ },
+ {
+  "frm": 63.0,
+  "to": 72.0,
+  "code": "01586",
+  "city": "勇払郡むかわ町",
+  "lv": "穂別稲里",
+  "kana": "ほべついなさと"
+ },
+ {
+  "frm": 72.25,
+  "to": 76.0,
+  "code": "01586",
+  "city": "勇払郡むかわ町",
+  "lv": "穂別長和",
+  "kana": "ほべつおさわ"
+ },
+ {
+  "frm": 76.25,
+  "to": 88.75,
+  "code": "01586",
+  "city": "勇払郡むかわ町",
+  "lv": "穂別福山",
+  "kana": "ほべつふくやま"
+ },
+ {
+  "frm": 89.0,
+  "to": 96.75,
+  "code": "01463",
+  "city": "勇払郡占冠村",
+  "lv": "字中央",
+  "kana": "ちゅうおう"
+ },
+ {
+  "frm": 97.0,
+  "to": 101.75,
+  "code": "01601",
+  "city": "沙流郡日高町",
+  "lv": "字日高",
+  "kana": "ひだか(1く)"
+ },
+ {
+  "frm": 102.0,
+  "to": 102.5,
+  "code": "01601",
+  "city": "沙流郡日高町",
+  "lv": "新町三丁目",
+  "kana": "しんまち"
+ },
+ {
+  "frm": 102.75,
+  "to": 102.75,
+  "code": "01601",
+  "city": "沙流郡日高町",
+  "lv": "新町一丁目",
+  "kana": "しんまち"
+ },
+ {
+  "frm": 103.0,
+  "to": 103.0,
+  "code": "01601",
+  "city": "沙流郡日高町",
+  "lv": "栄町東一丁目",
+  "kana": "さかえまちひがし"
+ },
+ {
+  "frm": 103.25,
+  "to": 103.5,
+  "code": "01601",
+  "city": "沙流郡日高町",
+  "lv": "本町東一丁目",
+  "kana": "ほんちょうひがし"
+ },
+ {
+  "frm": 103.75,
+  "to": 103.75,
+  "code": "01601",
+  "city": "沙流郡日高町",
+  "lv": "本町東二丁目",
+  "kana": "ほんちょうひがし"
+ },
+ {
+  "frm": 104.0,
+  "to": 104.0,
+  "code": "01601",
+  "city": "沙流郡日高町",
+  "lv": "松風町一丁目",
+  "kana": "まつかぜちょう"
+ },
+ {
+  "frm": 104.25,
+  "to": 104.25,
+  "code": "01601",
+  "city": "沙流郡日高町",
+  "lv": "山手町一丁目",
+  "kana": "やまてちょう"
+ },
+ {
+  "frm": 104.5,
+  "to": 107.0,
+  "code": "01601",
+  "city": "沙流郡日高町",
+  "lv": "字日高",
+  "kana": "ひだか(1く)"
+ },
+ {
+  "frm": 107.25,
+  "to": 107.75,
+  "code": "01601",
+  "city": "沙流郡日高町",
+  "lv": "字千栄",
+  "kana": "ちさか"
+ }
+]