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/064/01_bbc-com.txt

@@ -0,0 +1,43 @@
+Man convicted after cryptocurrency robbery
+
+A 28-year-old man from Lanarkshire has been convicted after having up to £1.2m worth of cryptocurrency in his account following a violent robbery.
+
+John Ross D'Alfonso was described as the "technical" brains behind the crime - thought to be the first robbery in Scotland involving stolen cryptocurrency.
+
+He had denied being part of the raid itself but was found guilty of reset, meaning he knowingly had something that was stolen and intended to keep it.
+
+The High Court in Glasgow heard that three men went into a home in Blantyre in Lanarkshire and forced the homeowner to transfer his Bitcoin, a form of digital cash, to D'Alfonso's account.
+
+The court was told that one of the men in the house was armed with a machete, and another repeatedly struck a woman on the head with a personalised Toblerone bar until it was covered in blood.
+
+The three men then escaped in an expensive Audi car belonging to the homeowner after the cash was transferred.
+
+The court heard that because of the unstable nature of the value of Bitcoin, it could have been worth anywhere between £100,000 and £1.2m when stolen on 18 March 2020.
+
+Bitcoin to blockchain: What key crypto words mean
+
+NatWest limits crypto transfers over scam fears
+
+Drugs gang jailed for £5m cryptocurrency operation
+
+D'Alfonso, who was a delivery driver from Cambuslang, had been described as the technical mind behind the robbery and denied being involved on the day.
+
+He insisted a "scary" relative had forced him to put the money into his account.
+
+Jurors were told there was "no dispute" the digital cash had been stolen and that it ended up in D'Alfonso's account and was transferred elsewhere.
+
+Prosecutors said D'Alfonso had not been at the robbery that night and instead gave "technical expertise" to help steal the money.
+
+D'Alfonso was cleared of robbery and assault charges and will be sentenced later this month in Edinburgh.
+
+Det Insp Craig Potter, of Police Scotland’s Cyber Investigations unit called the case a complex investigation.
+
+"This is a complex and constantly evolving technology," he said.
+
+"Specialist cybercrime officers were able to follow the movement of funds to show he had been responsible for the bitcoin wallet which received the stolen funds.
+
+"This conviction demonstrates Police Scotland capability and commitment to tackling criminality involving the digital space and bringing criminals operating in this world to justice."
+
+Turkish crypto boss handed 11,196 years in prison
+
+Drug dealer ordered to pay back dark web millions

merge-output/staging/064/index.json

@@ -0,0 +1,16 @@
+[
+  {
+    "case": 64,
+    "n": 1,
+    "field": "url",
+    "url": "https://www.bbc.com/news/articles/cw5w5zyg979o",
+    "host": "bbc.com",
+    "fetched_at": "2026-09-05T12:54:31+00:00",
+    "verdict": "FETCHED",
+    "method": "raw",
+    "http": 200,
+    "chars": 2566,
+    "sha256": "0ea40d48faa18a047ddb781aeed768a9e66ba57f5aee90c987c029bb9128214b",
+    "final_url": null
+  }
+]