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/298/01_khaleejtimes-com.txt

@@ -0,0 +1,33 @@
+Dubai: Dh4 million stolen from Bitcoin trader; 9 people jailed | Khaleej Times
+
+Dubai: Dh4 million stolen from Bitcoin trader; 9 people jailed
+
+The robbers knocked on the door of his company's headquarters before entering and assaulting him; they will be deported after serving their sentences
+
+PUBLISHED: Mon 3 Oct 2022, 8:10 AM UPDATED: Mon 3 Oct 2022, 8:16 PM
+
+A gang comprising nine people stole Dh 4,120,000 from the owner of a Bitcoin trading company in the Al Nakhil area in Dubai. They assaulted him while he was at work.
+
+The details of the case date back to last April, when the victim filed a report stating that he had been assaulted and robbed by force at his company's headquarters.
+
+UAE President pardons Abdul Rahman Yusuf Al Qaradawi after criminal conviction
+
+Sharjah Ruler approves Dh20,000 monthly living allowance for govt employees, other groups
+
+US VP Vance says would not 'call it a war' with Iran, on categorising hostilities
+
+Sharjah Police arrest man accused of killing two Kazakh sisters
+
+US military disables 3 vessels, redirects 87 in ongoing Iran blockade
+
+According to the victim's statement, he was surprised by nine robbers knocking on the door of his company and entering. They attacked him and stole the cash.
+
+The police identified them and arrested them. The Dubai Criminal Court convicted them and sentenced to three years in prison, and deportation from the state after serving their sentences.
+
+Dubai: Two jailed for threatening to kill couple, stealing Dh8,000 from them
+
+UAE: New mobile police station launched in Sharjah
+
+Trump says US may hit Iran's Pickaxe Mountain soon
+
+UAE latest flight updates: Almost 20 services delayed or cancelled after renewed US-Iran attacks

merge-output/staging/298/index.json

@@ -0,0 +1,16 @@
+[
+  {
+    "case": 298,
+    "n": 1,
+    "field": "url",
+    "url": "https://www.khaleejtimes.com/uae/crime/dubai-dh4-million-stolen-from-bitcoin-trader-9-people-jailed",
+    "host": "khaleejtimes.com",
+    "fetched_at": "2026-09-05T12:44:30+00:00",
+    "verdict": "FETCHED",
+    "method": "raw",
+    "http": 200,
+    "chars": 1714,
+    "sha256": "2cc6738367d278a2803d4aa6db24df2ab173b29ee90b74830541fecce200fcae",
+    "final_url": null
+  }
+]