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/078/01_cointelegraph-com.txt

@@ -0,0 +1,25 @@
+Polish crypto exchange employee in induced coma after armed attack
+
+Written by Marie Huilletformer writerReviewed by Alex Cohenformer editor
+
+On Jan. 22, an attacker shot two employees at a cryptocurrency and gold exchange in the Polish city of Olsztyn, escaping with over $120,000 in gold.
+
+Polish police have detained a suspect in an armed attack on FlyingAtom, a cryptocurrency and gold exchange in the city of Olsztyn in northeastern Poland. The incident, which occurred around 7 p.m. local time on Jan. 22, resulted in the injuries of two employees — one of whose situation was severe enough to necessitate an induced coma.
+
+According to local media reports from Jan. 23, the masked attacker escaped with gold worth 450,000 zloty (roughly $120,000), fleeing the exchange's office on the fourth floor of a skyscraper in the city center. Following the incident, police secured the area and scoured surveillance footage, cordoning off multiple roads in the city and searching passing cars. Roads were re-opened by the following morning.
+
+On Jan. 23, FlyingAtom publicized an announcement offering a prize of 100,000 zloty for any information that could help to identify the perpetrator.
+
+A local crypto outlet reported on Jan. 24 that a suspect was subsequently detained in connection with the investigation. The outlet cited the press spokesman of the Municipal Police Headquarters in Olsztyn, Andrzej Jurkun, with a comment on the evening of Jan. 23 that “in Bydgoszcz [the police] detained a man who may be related to the attack. We do not provide more information, activities are underway. "
+
+On Jan. 25, FlyingAtom published a Facebook post thanking the police for their successful capture of the suspect, as well as medical authorities for their ongoing care of the injured victims, appearing to confirm the earlier report of the suspect's detention. Since the attack, the exchange's office has been closed and will likely resume operations in early March, according to a post from Feb. 1.
+
+While many criminal incidents related to cryptocurrency are perpetrated online, there is nonetheless a persistent risk of physical robbery in the industry. In late January, an armed gang posing as cryptocurrency buyers stole about 3.5 million Hong Kong dollars ($450,000) from a woman in Hong Kong. While she was luckily unscathed during the incident, other victims of cryptocurrency-related attacks have suffered kidnap and torture, or been forced to escape in highly dangerous circumstances.
+
+Cointelegraph is committed to independent, transparent journalism. This news article is produced in accordance with Cointelegraph’s Editorial Policy and aims to provide accurate and timely information. Readers are encouraged to verify information independently.
+
+Bitcoin ETF inflows hit $3.8B in strongest three-week stretch of 2026
+
+Bitcoin ETF inflows hit $731M, highest since January as BTC reclaims $80K
+
+Bitcoin reclaims $80K as DXY falls amid continuing suspected yen intervention

merge-output/staging/078/index.json

@@ -0,0 +1,16 @@
+[
+  {
+    "case": 78,
+    "n": 1,
+    "field": "url",
+    "url": "https://cointelegraph.com/news/polish-crypto-exchange-employee-in-induced-coma-after-armed-attack",
+    "host": "cointelegraph.com",
+    "fetched_at": "2026-09-05T12:54:10+00:00",
+    "verdict": "FETCHED",
+    "method": "raw",
+    "http": 200,
+    "chars": 2980,
+    "sha256": "39f4a25b22d42787907a5c01bb7a20ba1dd4229bc230644f8051e71a0fbaecb0",
+    "final_url": null
+  }
+]