feat(sources): fetch linked URLs for the 252 spreadsheet-only cases

Until now only cases 357+ (plus a few older ones) had their linked URLs
fetched; the other 252 dossiers held just the text pasted into the
spreadsheet, often only the lede. This pass fetches every linked URL for
those cases so the full text is on file before link rot takes it.

- stage_all.py: new --include-sheet-cases flag that lifts the skip on
  cases holding spreadsheet articles. Resumable as before.
- staging/: raw extracts and index.json for the 252 cases.
- sourced-articles.json, case-files-manifest.json: 188 new UNTRIMMED
  blocks. 179 cases gained at least one fetched article; 73 got none
  (49 BLOCKED, 18 THIN, 9 DEAD, 4 video/social, 3 ERROR).
- sources/*.txt: rebuilt with build_cases.py --all. Sheet pastes are
  kept; fetched blocks sit beside them under the NOT YET TRIMMED banner.
  Files previously committed with CRLF are now LF.
- wayback-availability.json: Wayback snapshots exist for 73 of the 98
  failed URL slots; input for an archive-fetch pass.
- README-START-HERE.md: progress note and next step.

verify_all.py PASSES (1836 checks).

Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01GZZENdTLzNGsbNy4DyF1yt

merge-output/staging/150/01_coconuts-co.txt

@@ -0,0 +1,27 @@
+Russian couple forced to part with US$284,399 in bitcoin after 4 men broke into their Kerobokan villa | Coconuts
+
+Russian couple forced to part with US$284,399 in bitcoin after 4 men broke into their Kerobokan villa
+
+Police in Bali said that two Russian nationals were victims of breaking and entering and robbery at their villa in Badung last week.
+
+The perpetrators, police said, forced the victims to part with their bitcoin, which was valued at US$284,399.
+
+The incident became public knowledge after Yuri Boytsov, 27, claimed via his Instagram account @boutsov_life that four men broke into his residence on Feb. 25. Three of them reportedly spoke Russian, while one man – who appears to be a local – was wearing a police uniform.
+
+The men threatened Boytsov and his girlfriend, Ekateryna Khmelenko, 27, before stealing their passports and other documents in addition to taking away Boytsov’s valuable crypto assets.
+
+Bali Police spokesman Stefanus Satake Bayu Setianto confirmed the incident, adding that the authorities received a report about it on Feb. 26.
+
+A Russian national identified by his initials SMA was reportedly arrested that day at the Ngurah Rai International Airport, where he was going to take a flight to Dubai. The other three suspects are believed to still be at large.
+
+Boytsov shared his story with a Russian news outlet. The police spokesman said that while he has every right to do so, they are concerned that it could actually hinder the investigation.
+
+“We are still investigating,” said Bayu.
+
+Get the best of Coconuts delivered to your inbox!
+
+Support local news and join a community of like-minded
+
+“Coconauts” across Southeast Asia and Hong Kong.
+
+Pay what you want, starting at US$5 / year.

merge-output/staging/150/index.json

@@ -0,0 +1,16 @@
+[
+  {
+    "case": 150,
+    "n": 1,
+    "field": "url",
+    "url": "https://coconuts.co/bali/news/russian-couple-forced-to-part-with-us284399-in-bitcoin-after-4-men-broke-into-their-kerobokan-villa/",
+    "host": "coconuts.co",
+    "fetched_at": "2026-09-05T12:51:32+00:00",
+    "verdict": "FETCHED",
+    "method": "raw",
+    "http": 200,
+    "chars": 1728,
+    "sha256": "982b056558d6349c4ee63f64e2a299cb949b9b402abe1937e48cd65458ea9a76",
+    "final_url": null
+  }
+]