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/059/01_vanguardngr-com.txt

@@ -0,0 +1,35 @@
+4 arrested over killing of Delta PDP member - Vanguard News
+
+Home » News » 4 arrested over killing of Delta PDP member
+
+4 arrested over killing of Delta PDP member
+
+Four persons have been arrested in connection with the killing of a member of the Peoples Democratic Party, PDP in Abraka, Ethiope East local government area of Delta State.
+
+The victim, Iroro Wisdom Ovie, a father of two, was beaten and shot by unknown gunmen last month at his Lucas area residence along the Police Station axis of Abraka.
+
+Confirming the arrest of the suspects yesterday, a security source at the Abraka police station disclosed that eight members of the Vikings confraternity were fingered in the incident, adding that four of the suspects including a bosom friend of the victim have been arrested and are currently in police custody.
+
+He said: “Two of the suspects are members of the anti-cult group while the other arrested suspect is the leader of the Vikings confraternity in the area.
+
+ALSO READ: We deserve SUVs, not cars for oversight functions — Reps
+
+“Investigations so far have also revealed that the bosom friend of the victim arrested had hinted one of the suspects of the discovery of $10, 000 in the victim’s Bitcoin wallet and then contacted the other suspects for the robbery operation.
+
+“From the confessional statements of the suspects, their intentions for carrying out the operation was to dispossess Iroro of the $10, 000 in his Bitcoin wallet but were disappointed to find out that what was left when they struck was $400.
+
+“According to them, they were forced to shoot him twice as he made an attempt to identify them while they were trying to open his account through his phone.
+
+“They eventually left with the phone and days later planned to sell the phone to a buyer, who rather than purchasing it decided to contact security operatives. With the help of the anti-cult group, the police were able to arrest four of the suspects.”
+
+Contacted, the Delta State Police Public Relations Officer, Onome Onovwakpoyeya, promised to get details of the incident, but she was yet to as at press time.
+
+Vanguard News Nigeria.
+
+Ebonyi Police arrest 620 suspects, recover 31 firearms
+
+Soldiers kill 324 terrorists, arrest 375, rescue 621 kidnapped victims in August
+
+Two suspects arrested over 55-year-old man’s abduction in Ondo
+
+Comments expressed here do not reflect the opinions of Vanguard newspapers or any employee thereof.

merge-output/staging/059/index.json

@@ -0,0 +1,16 @@
+[
+  {
+    "case": 59,
+    "n": 1,
+    "field": "url",
+    "url": "https://www.vanguardngr.com/2020/02/4-arrested-over-killing-of-delta-pdp-member/",
+    "host": "vanguardngr.com",
+    "fetched_at": "2026-09-05T12:54:41+00:00",
+    "verdict": "FETCHED",
+    "method": "raw",
+    "http": 200,
+    "chars": 2427,
+    "sha256": "1e7a3ff6ff3e046910828826252887d4baf872597fd0a66e050f6f849f861100",
+    "final_url": null
+  }
+]