ledger: extract albums->photos join table (100 albums x 50 photos)

wizard-work/ledger/2026-10-31-albums-photo-counts.csv

@@ -0,0 +1,101 @@
+id,userId,title,photo_count
+1,1,quidem molestiae enim,50
+2,1,sunt qui excepturi placeat culpa,50
+3,1,omnis laborum odio,50
+4,1,non esse culpa molestiae omnis sed optio,50
+5,1,eaque aut omnis a,50
+6,1,natus impedit quibusdam illo est,50
+7,1,quibusdam autem aliquid et et quia,50
+8,1,qui fuga est a eum,50
+9,1,saepe unde necessitatibus rem,50
+10,1,distinctio laborum qui,50
+11,2,quam nostrum impedit mollitia quod et dolor,50
+12,2,consequatur autem doloribus natus consectetur,50
+13,2,ab rerum non rerum consequatur ut ea unde,50
+14,2,ducimus molestias eos animi atque nihil,50
+15,2,ut pariatur rerum ipsum natus repellendus praesentium,50
+16,2,voluptatem aut maxime inventore autem magnam atque repellat,50
+17,2,aut minima voluptatem ut velit,50
+18,2,nesciunt quia et doloremque,50
+19,2,velit pariatur quaerat similique libero omnis quia,50
+20,2,voluptas rerum iure ut enim,50
+21,3,repudiandae voluptatem optio est consequatur rem in temporibus et,50
+22,3,et rem non provident vel ut,50
+23,3,incidunt quisquam hic adipisci sequi,50
+24,3,dolores ut et facere placeat,50
+25,3,vero maxime id possimus sunt neque et consequatur,50
+26,3,quibusdam saepe ipsa vel harum,50
+27,3,id non nostrum expedita,50
+28,3,omnis neque exercitationem sed dolor atque maxime aut cum,50
+29,3,inventore ut quasi magnam itaque est fugit,50
+30,3,tempora assumenda et similique odit distinctio error,50
+31,4,adipisci laborum fuga laboriosam,50
+32,4,reiciendis dolores a ut qui debitis non quo labore,50
+33,4,iste eos nostrum,50
+34,4,cumque voluptatibus rerum architecto blanditiis,50
+35,4,et impedit nisi quae magni necessitatibus sed aut pariatur,50
+36,4,nihil cupiditate voluptate neque,50
+37,4,est placeat dicta ut nisi rerum iste,50
+38,4,unde a sequi id,50
+39,4,ratione porro illum labore eum aperiam sed,50
+40,4,voluptas neque et sint aut quo odit,50
+41,5,ea voluptates maiores eos accusantium officiis tempore mollitia consequatur,50
+42,5,tenetur explicabo ea,50
+43,5,aperiam doloremque nihil,50
+44,5,sapiente cum numquam officia consequatur vel natus quos suscipit,50
+45,5,tenetur quos ea unde est enim corrupti qui,50
+46,5,molestiae voluptate non,50
+47,5,temporibus molestiae aut,50
+48,5,modi consequatur culpa aut quam soluta alias perspiciatis laudantium,50
+49,5,ut aut vero repudiandae voluptas ullam voluptas at consequatur,50
+50,5,sed qui sed quas sit ducimus dolor,50
+51,6,odit laboriosam sint quia cupiditate animi quis,50
+52,6,necessitatibus quas et sunt at voluptatem,50
+53,6,est vel sequi voluptatem nemo quam molestiae modi enim,50
+54,6,aut non illo amet perferendis,50
+55,6,qui culpa itaque omnis in nesciunt architecto error,50
+56,6,omnis qui maiores tempora officiis omnis rerum sed repellat,50
+57,6,libero excepturi voluptatem est architecto quae voluptatum officia tempora,50
+58,6,nulla illo consequatur aspernatur veritatis aut error delectus et,50
+59,6,eligendi similique provident nihil,50
+60,6,omnis mollitia sunt aliquid eum consequatur fugit minus laudantium,50
+61,7,delectus iusto et,50
+62,7,eos ea non recusandae iste ut quasi,50
+63,7,velit est quam,50
+64,7,autem voluptatem amet iure quae,50
+65,7,voluptates delectus iure iste qui,50
+66,7,velit sed quia dolor dolores delectus,50
+67,7,ad voluptas nostrum et nihil,50
+68,7,qui quasi nihil aut voluptatum sit dolore minima,50
+69,7,qui aut est,50
+70,7,et deleniti unde,50
+71,8,et vel corporis,50
+72,8,unde exercitationem ut,50
+73,8,quos omnis officia,50
+74,8,quia est eius vitae dolor,50
+75,8,aut quia expedita non,50
+76,8,dolorem magnam facere itaque ut reprehenderit tenetur corrupti,50
+77,8,cupiditate sapiente maiores iusto ducimus cum excepturi veritatis quia,50
+78,8,est minima eius possimus ea ratione velit et,50
+79,8,ipsa quae voluptas natus ut suscipit soluta quia quidem,50
+80,8,id nihil reprehenderit,50
+81,9,quibusdam sapiente et,50
+82,9,recusandae consequatur vel amet unde,50
+83,9,aperiam odio fugiat,50
+84,9,est et at eos expedita,50
+85,9,qui voluptatem consequatur aut ab quis temporibus praesentium,50
+86,9,eligendi mollitia alias aspernatur vel ut iusto,50
+87,9,aut aut architecto,50
+88,9,quas perspiciatis optio,50
+89,9,sit optio id voluptatem est eum et,50
+90,9,est vel dignissimos,50
+91,10,repellendus praesentium debitis officiis,50
+92,10,incidunt et et eligendi assumenda soluta quia recusandae,50
+93,10,nisi qui dolores perspiciatis,50
+94,10,quisquam a dolores et earum vitae,50
+95,10,consectetur vel rerum qui aperiam modi eos aspernatur ipsa,50
+96,10,unde et ut molestiae est molestias voluptatem sint,50
+97,10,est quod aut,50
+98,10,omnis quia possimus nesciunt deleniti assumenda sed autem,50
+99,10,consectetur ut id impedit dolores sit ad ex aut,50
+100,10,enim repellat iste,50

wizard-work/ledger/2026-10-31-albums-photo-counts.json

@@ -0,0 +1,602 @@
+[
+  {
+    "id": 1,
+    "userId": 1,
+    "title": "quidem molestiae enim",
+    "photo_count": 50
+  },
+  {
+    "id": 2,
+    "userId": 1,
+    "title": "sunt qui excepturi placeat culpa",
+    "photo_count": 50
+  },
+  {
+    "id": 3,
+    "userId": 1,
+    "title": "omnis laborum odio",
+    "photo_count": 50
+  },
+  {
+    "id": 4,
+    "userId": 1,
+    "title": "non esse culpa molestiae omnis sed optio",
+    "photo_count": 50
+  },
+  {
+    "id": 5,
+    "userId": 1,
+    "title": "eaque aut omnis a",
+    "photo_count": 50
+  },
+  {
+    "id": 6,
+    "userId": 1,
+    "title": "natus impedit quibusdam illo est",
+    "photo_count": 50
+  },
+  {
+    "id": 7,
+    "userId": 1,
+    "title": "quibusdam autem aliquid et et quia",
+    "photo_count": 50
+  },
+  {
+    "id": 8,
+    "userId": 1,
+    "title": "qui fuga est a eum",
+    "photo_count": 50
+  },
+  {
+    "id": 9,
+    "userId": 1,
+    "title": "saepe unde necessitatibus rem",
+    "photo_count": 50
+  },
+  {
+    "id": 10,
+    "userId": 1,
+    "title": "distinctio laborum qui",
+    "photo_count": 50
+  },
+  {
+    "id": 11,
+    "userId": 2,
+    "title": "quam nostrum impedit mollitia quod et dolor",
+    "photo_count": 50
+  },
+  {
+    "id": 12,
+    "userId": 2,
+    "title": "consequatur autem doloribus natus consectetur",
+    "photo_count": 50
+  },
+  {
+    "id": 13,
+    "userId": 2,
+    "title": "ab rerum non rerum consequatur ut ea unde",
+    "photo_count": 50
+  },
+  {
+    "id": 14,
+    "userId": 2,
+    "title": "ducimus molestias eos animi atque nihil",
+    "photo_count": 50
+  },
+  {
+    "id": 15,
+    "userId": 2,
+    "title": "ut pariatur rerum ipsum natus repellendus praesentium",
+    "photo_count": 50
+  },
+  {
+    "id": 16,
+    "userId": 2,
+    "title": "voluptatem aut maxime inventore autem magnam atque repellat",
+    "photo_count": 50
+  },
+  {
+    "id": 17,
+    "userId": 2,
+    "title": "aut minima voluptatem ut velit",
+    "photo_count": 50
+  },
+  {
+    "id": 18,
+    "userId": 2,
+    "title": "nesciunt quia et doloremque",
+    "photo_count": 50
+  },
+  {
+    "id": 19,
+    "userId": 2,
+    "title": "velit pariatur quaerat similique libero omnis quia",
+    "photo_count": 50
+  },
+  {
+    "id": 20,
+    "userId": 2,
+    "title": "voluptas rerum iure ut enim",
+    "photo_count": 50
+  },
+  {
+    "id": 21,
+    "userId": 3,
+    "title": "repudiandae voluptatem optio est consequatur rem in temporibus et",
+    "photo_count": 50
+  },
+  {
+    "id": 22,
+    "userId": 3,
+    "title": "et rem non provident vel ut",
+    "photo_count": 50
+  },
+  {
+    "id": 23,
+    "userId": 3,
+    "title": "incidunt quisquam hic adipisci sequi",
+    "photo_count": 50
+  },
+  {
+    "id": 24,
+    "userId": 3,
+    "title": "dolores ut et facere placeat",
+    "photo_count": 50
+  },
+  {
+    "id": 25,
+    "userId": 3,
+    "title": "vero maxime id possimus sunt neque et consequatur",
+    "photo_count": 50
+  },
+  {
+    "id": 26,
+    "userId": 3,
+    "title": "quibusdam saepe ipsa vel harum",
+    "photo_count": 50
+  },
+  {
+    "id": 27,
+    "userId": 3,
+    "title": "id non nostrum expedita",
+    "photo_count": 50
+  },
+  {
+    "id": 28,
+    "userId": 3,
+    "title": "omnis neque exercitationem sed dolor atque maxime aut cum",
+    "photo_count": 50
+  },
+  {
+    "id": 29,
+    "userId": 3,
+    "title": "inventore ut quasi magnam itaque est fugit",
+    "photo_count": 50
+  },
+  {
+    "id": 30,
+    "userId": 3,
+    "title": "tempora assumenda et similique odit distinctio error",
+    "photo_count": 50
+  },
+  {
+    "id": 31,
+    "userId": 4,
+    "title": "adipisci laborum fuga laboriosam",
+    "photo_count": 50
+  },
+  {
+    "id": 32,
+    "userId": 4,
+    "title": "reiciendis dolores a ut qui debitis non quo labore",
+    "photo_count": 50
+  },
+  {
+    "id": 33,
+    "userId": 4,
+    "title": "iste eos nostrum",
+    "photo_count": 50
+  },
+  {
+    "id": 34,
+    "userId": 4,
+    "title": "cumque voluptatibus rerum architecto blanditiis",
+    "photo_count": 50
+  },
+  {
+    "id": 35,
+    "userId": 4,
+    "title": "et impedit nisi quae magni necessitatibus sed aut pariatur",
+    "photo_count": 50
+  },
+  {
+    "id": 36,
+    "userId": 4,
+    "title": "nihil cupiditate voluptate neque",
+    "photo_count": 50
+  },
+  {
+    "id": 37,
+    "userId": 4,
+    "title": "est placeat dicta ut nisi rerum iste",
+    "photo_count": 50
+  },
+  {
+    "id": 38,
+    "userId": 4,
+    "title": "unde a sequi id",
+    "photo_count": 50
+  },
+  {
+    "id": 39,
+    "userId": 4,
+    "title": "ratione porro illum labore eum aperiam sed",
+    "photo_count": 50
+  },
+  {
+    "id": 40,
+    "userId": 4,
+    "title": "voluptas neque et sint aut quo odit",
+    "photo_count": 50
+  },
+  {
+    "id": 41,
+    "userId": 5,
+    "title": "ea voluptates maiores eos accusantium officiis tempore mollitia consequatur",
+    "photo_count": 50
+  },
+  {
+    "id": 42,
+    "userId": 5,
+    "title": "tenetur explicabo ea",
+    "photo_count": 50
+  },
+  {
+    "id": 43,
+    "userId": 5,
+    "title": "aperiam doloremque nihil",
+    "photo_count": 50
+  },
+  {
+    "id": 44,
+    "userId": 5,
+    "title": "sapiente cum numquam officia consequatur vel natus quos suscipit",
+    "photo_count": 50
+  },
+  {
+    "id": 45,
+    "userId": 5,
+    "title": "tenetur quos ea unde est enim corrupti qui",
+    "photo_count": 50
+  },
+  {
+    "id": 46,
+    "userId": 5,
+    "title": "molestiae voluptate non",
+    "photo_count": 50
+  },
+  {
+    "id": 47,
+    "userId": 5,
+    "title": "temporibus molestiae aut",
+    "photo_count": 50
+  },
+  {
+    "id": 48,
+    "userId": 5,
+    "title": "modi consequatur culpa aut quam soluta alias perspiciatis laudantium",
+    "photo_count": 50
+  },
+  {
+    "id": 49,
+    "userId": 5,
+    "title": "ut aut vero repudiandae voluptas ullam voluptas at consequatur",
+    "photo_count": 50
+  },
+  {
+    "id": 50,
+    "userId": 5,
+    "title": "sed qui sed quas sit ducimus dolor",
+    "photo_count": 50
+  },
+  {
+    "id": 51,
+    "userId": 6,
+    "title": "odit laboriosam sint quia cupiditate animi quis",
+    "photo_count": 50
+  },
+  {
+    "id": 52,
+    "userId": 6,
+    "title": "necessitatibus quas et sunt at voluptatem",
+    "photo_count": 50
+  },
+  {
+    "id": 53,
+    "userId": 6,
+    "title": "est vel sequi voluptatem nemo quam molestiae modi enim",
+    "photo_count": 50
+  },
+  {
+    "id": 54,
+    "userId": 6,
+    "title": "aut non illo amet perferendis",
+    "photo_count": 50
+  },
+  {
+    "id": 55,
+    "userId": 6,
+    "title": "qui culpa itaque omnis in nesciunt architecto error",
+    "photo_count": 50
+  },
+  {
+    "id": 56,
+    "userId": 6,
+    "title": "omnis qui maiores tempora officiis omnis rerum sed repellat",
+    "photo_count": 50
+  },
+  {
+    "id": 57,
+    "userId": 6,
+    "title": "libero excepturi voluptatem est architecto quae voluptatum officia tempora",
+    "photo_count": 50
+  },
+  {
+    "id": 58,
+    "userId": 6,
+    "title": "nulla illo consequatur aspernatur veritatis aut error delectus et",
+    "photo_count": 50
+  },
+  {
+    "id": 59,
+    "userId": 6,
+    "title": "eligendi similique provident nihil",
+    "photo_count": 50
+  },
+  {
+    "id": 60,
+    "userId": 6,
+    "title": "omnis mollitia sunt aliquid eum consequatur fugit minus laudantium",
+    "photo_count": 50
+  },
+  {
+    "id": 61,
+    "userId": 7,
+    "title": "delectus iusto et",
+    "photo_count": 50
+  },
+  {
+    "id": 62,
+    "userId": 7,
+    "title": "eos ea non recusandae iste ut quasi",
+    "photo_count": 50
+  },
+  {
+    "id": 63,
+    "userId": 7,
+    "title": "velit est quam",
+    "photo_count": 50
+  },
+  {
+    "id": 64,
+    "userId": 7,
+    "title": "autem voluptatem amet iure quae",
+    "photo_count": 50
+  },
+  {
+    "id": 65,
+    "userId": 7,
+    "title": "voluptates delectus iure iste qui",
+    "photo_count": 50
+  },
+  {
+    "id": 66,
+    "userId": 7,
+    "title": "velit sed quia dolor dolores delectus",
+    "photo_count": 50
+  },
+  {
+    "id": 67,
+    "userId": 7,
+    "title": "ad voluptas nostrum et nihil",
+    "photo_count": 50
+  },
+  {
+    "id": 68,
+    "userId": 7,
+    "title": "qui quasi nihil aut voluptatum sit dolore minima",
+    "photo_count": 50
+  },
+  {
+    "id": 69,
+    "userId": 7,
+    "title": "qui aut est",
+    "photo_count": 50
+  },
+  {
+    "id": 70,
+    "userId": 7,
+    "title": "et deleniti unde",
+    "photo_count": 50
+  },
+  {
+    "id": 71,
+    "userId": 8,
+    "title": "et vel corporis",
+    "photo_count": 50
+  },
+  {
+    "id": 72,
+    "userId": 8,
+    "title": "unde exercitationem ut",
+    "photo_count": 50
+  },
+  {
+    "id": 73,
+    "userId": 8,
+    "title": "quos omnis officia",
+    "photo_count": 50
+  },
+  {
+    "id": 74,
+    "userId": 8,
+    "title": "quia est eius vitae dolor",
+    "photo_count": 50
+  },
+  {
+    "id": 75,
+    "userId": 8,
+    "title": "aut quia expedita non",
+    "photo_count": 50
+  },
+  {
+    "id": 76,
+    "userId": 8,
+    "title": "dolorem magnam facere itaque ut reprehenderit tenetur corrupti",
+    "photo_count": 50
+  },
+  {
+    "id": 77,
+    "userId": 8,
+    "title": "cupiditate sapiente maiores iusto ducimus cum excepturi veritatis quia",
+    "photo_count": 50
+  },
+  {
+    "id": 78,
+    "userId": 8,
+    "title": "est minima eius possimus ea ratione velit et",
+    "photo_count": 50
+  },
+  {
+    "id": 79,
+    "userId": 8,
+    "title": "ipsa quae voluptas natus ut suscipit soluta quia quidem",
+    "photo_count": 50
+  },
+  {
+    "id": 80,
+    "userId": 8,
+    "title": "id nihil reprehenderit",
+    "photo_count": 50
+  },
+  {
+    "id": 81,
+    "userId": 9,
+    "title": "quibusdam sapiente et",
+    "photo_count": 50
+  },
+  {
+    "id": 82,
+    "userId": 9,
+    "title": "recusandae consequatur vel amet unde",
+    "photo_count": 50
+  },
+  {
+    "id": 83,
+    "userId": 9,
+    "title": "aperiam odio fugiat",
+    "photo_count": 50
+  },
+  {
+    "id": 84,
+    "userId": 9,
+    "title": "est et at eos expedita",
+    "photo_count": 50
+  },
+  {
+    "id": 85,
+    "userId": 9,
+    "title": "qui voluptatem consequatur aut ab quis temporibus praesentium",
+    "photo_count": 50
+  },
+  {
+    "id": 86,
+    "userId": 9,
+    "title": "eligendi mollitia alias aspernatur vel ut iusto",
+    "photo_count": 50
+  },
+  {
+    "id": 87,
+    "userId": 9,
+    "title": "aut aut architecto",
+    "photo_count": 50
+  },
+  {
+    "id": 88,
+    "userId": 9,
+    "title": "quas perspiciatis optio",
+    "photo_count": 50
+  },
+  {
+    "id": 89,
+    "userId": 9,
+    "title": "sit optio id voluptatem est eum et",
+    "photo_count": 50
+  },
+  {
+    "id": 90,
+    "userId": 9,
+    "title": "est vel dignissimos",
+    "photo_count": 50
+  },
+  {
+    "id": 91,
+    "userId": 10,
+    "title": "repellendus praesentium debitis officiis",
+    "photo_count": 50
+  },
+  {
+    "id": 92,
+    "userId": 10,
+    "title": "incidunt et et eligendi assumenda soluta quia recusandae",
+    "photo_count": 50
+  },
+  {
+    "id": 93,
+    "userId": 10,
+    "title": "nisi qui dolores perspiciatis",
+    "photo_count": 50
+  },
+  {
+    "id": 94,
+    "userId": 10,
+    "title": "quisquam a dolores et earum vitae",
+    "photo_count": 50
+  },
+  {
+    "id": 95,
+    "userId": 10,
+    "title": "consectetur vel rerum qui aperiam modi eos aspernatur ipsa",
+    "photo_count": 50
+  },
+  {
+    "id": 96,
+    "userId": 10,
+    "title": "unde et ut molestiae est molestias voluptatem sint",
+    "photo_count": 50
+  },
+  {
+    "id": 97,
+    "userId": 10,
+    "title": "est quod aut",
+    "photo_count": 50
+  },
+  {
+    "id": 98,
+    "userId": 10,
+    "title": "omnis quia possimus nesciunt deleniti assumenda sed autem",
+    "photo_count": 50
+  },
+  {
+    "id": 99,
+    "userId": 10,
+    "title": "consectetur ut id impedit dolores sit ad ex aut",
+    "photo_count": 50
+  },
+  {
+    "id": 100,
+    "userId": 10,
+    "title": "enim repellat iste",
+    "photo_count": 50
+  }
+]

wizard-work/ledger/2026-10-31-albums-photo-counts.md

@@ -0,0 +1,43 @@
+# Albums → Photos join (extract artifact) — ledger lane
+
+Per-album table: which album, its author (`userId`), its title, and the number of
+photos it contains. One row per album.
+
+## Sources
+
+- `https://jsonplaceholder.typicode.com/albums` — 100 albums
+- `https://jsonplaceholder.typicode.com/photos` — 5000 photos
+
+Join key: `photos.albumId == albums.id`.
+
+## Columns
+
+| Column | Meaning |
+|---|---|
+| `id` | album id (1–100) |
+| `userId` | album author |
+| `title` | album title |
+| `photo_count` | number of photos in the album |
+
+## Result (100 rows)
+
+- 100 albums, 5000 photos, 100 distinct album ids.
+- `photo_count` is **50 for every album** (uniform).
+
+## Artifacts (reproduced by `extract_albums_photo_counts.py`)
+
+- `2026-10-31-albums-photo-counts.csv` — the table (CSV)
+- `2026-10-31-albums-photo-counts.json` — the same table (JSON)
+
+## Verification (single command, exit 0 = correct)
+
+Run from the repo root:
+
+```bash
+bash wizard-work/ledger/CHECK-albums-photo-counts
+```
+
+The check re-fetches both endpoints, re-derives the table, and compares the
+committed CSV and JSON against the fresh extraction (parsed, so line endings and
+quoting do not affect the verdict). It also asserts the row counts, the total
+photo count and the uniform `photo_count` claim above.

wizard-work/ledger/CHECK-albums-photo-counts

@@ -0,0 +1,11 @@
+#!/usr/bin/env bash
+# CHECK -- albums->photos extract (Extract lane, 2026-10-31).
+# Re-fetches both JSONPlaceholder endpoints, re-derives the per-album table, and
+# compares the committed CSV + JSON against the fresh extraction. Exits 0 only
+# when the committed artifacts match. Exit code IS the verdict.
+set -u
+
+DIR=$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)
+cd "$DIR/../.." || exit 1
+
+python3 wizard-work/ledger/verify_albums_photo_counts.py

wizard-work/ledger/extract_albums_photo_counts.py

@@ -0,0 +1,77 @@
+#!/usr/bin/env python3
+"""Extract: JSONPlaceholder albums -> photos join.
+
+Builds a per-album table: which album, its author (userId), its title, and the
+number of photos it contains. Sources:
+
+  https://jsonplaceholder.typicode.com/albums   (100 albums)
+  https://jsonplaceholder.typicode.com/photos   (5000 photos)
+
+Join key: photos.albumId == albums.id
+
+One row per album (100 rows). photo_count is 50 for every album (uniform).
+Outputs: CSV + JSON of the same table.
+"""
+
+import csv
+import json
+import os
+import urllib.request
+from collections import Counter, defaultdict
+
+ALBUMS_URL = "https://jsonplaceholder.typicode.com/albums"
+PHOTOS_URL = "https://jsonplaceholder.typicode.com/photos"
+
+BASE = os.path.dirname(os.path.abspath(__file__))
+
+
+def fetch(url):
+    req = urllib.request.Request(url, headers={"User-Agent": "ledger/extract"})
+    with urllib.request.urlopen(req, timeout=30) as r:
+        return json.load(r)
+
+
+def main():
+    albums = fetch(ALBUMS_URL)
+    photos = fetch(PHOTOS_URL)
+
+    # sanity: every photo must resolve to a known album
+    album_ids = {a["id"] for a in albums}
+    unknown = sorted({p["albumId"] for p in photos} - album_ids)
+    if unknown:
+        raise SystemExit("photo albumIds not in albums: %s" % unknown[:5])
+
+    counts = Counter(p["albumId"] for p in photos)
+    total = sum(counts.values())
+
+    rows = []
+    for a in sorted(albums, key=lambda x: x["id"]):
+        rows.append({
+            "id": a["id"],
+            "userId": a["userId"],
+            "title": a["title"],
+            "photo_count": counts.get(a["id"], 0),
+        })
+
+    csv_path = os.path.join(BASE, "2026-10-31-albums-photo-counts.csv")
+    json_path = os.path.join(BASE, "2026-10-31-albums-photo-counts.json")
+
+    with open(csv_path, "w", newline="", encoding="utf-8") as f:
+        w = csv.DictWriter(f, fieldnames=["id", "userId", "title", "photo_count"])
+        w.writeheader()
+        w.writerows(rows)
+
+    payload = json.dumps(rows, ensure_ascii=False, indent=2).encode("utf-8")
+    with open(json_path, "wb") as f:
+        f.write(payload)
+
+    with open(csv_path, encoding="utf-8") as f:
+        csv_bytes = len(f.read())
+    print("wrote %s (%d bytes, %d rows)" % (csv_path, csv_bytes, len(rows)))
+    print("wrote %s (%d bytes)" % (json_path, len(payload)))
+    print("total photos = %d across %d albums (uniform photo_count=%d)"
+          % (total, len(rows), rows[0]["photo_count"] if rows else None))
+
+
+if __name__ == "__main__":
+    main()

wizard-work/ledger/verify_albums_photo_counts.py

@@ -0,0 +1,96 @@
+#!/usr/bin/env python3
+"""Independent verifier for the albums->photos extract artifact (ledger lane).
+
+Re-fetches both JSONPlaceholder endpoints, re-derives the per-album table, and
+compares the committed CSV + JSON against the fresh extraction (parsed, so line
+endings and quoting do not affect the verdict). Also asserts the row counts,
+the total photo count and the uniform photo_count claim above. Exits 0 only when
+the committed artifacts match the fresh extraction.
+"""
+
+import csv
+import json
+import sys
+import urllib.request
+from collections import Counter
+
+BASE = "/root/troupe-standup/wizard-work/ledger"
+CSV_PATH = BASE + "/2026-10-31-albums-photo-counts.csv"
+JSON_PATH = BASE + "/2026-10-31-albums-photo-counts.json"
+
+ALBUMS_URL = "https://jsonplaceholder.typicode.com/albums"
+PHOTOS_URL = "https://jsonplaceholder.typicode.com/photos"
+
+
+def fetch(url):
+    req = urllib.request.Request(url, headers={"User-Agent": "ledger/extract"})
+    with urllib.request.urlopen(req, timeout=30) as r:
+        return json.load(r)
+
+
+def read_csv_rows(path):
+    with open(path, encoding="utf-8") as f:
+        return list(csv.DictReader(f))
+
+
+def main():
+    albums = fetch(ALBUMS_URL)
+    photos = fetch(PHOTOS_URL)
+
+    album_ids = {a["id"] for a in albums}
+    unknown = sorted({p["albumId"] for p in photos} - album_ids)
+    if unknown:
+        print("FAIL: photo albumIds not present in albums: %s" % unknown[:5])
+        return 1
+
+    counts = Counter(p["albumId"] for p in photos)
+    total = sum(counts.values())
+
+    # Fresh extraction result (same field types the extractor writes).
+    raw_rows = []
+    for a in sorted(albums, key=lambda x: x["id"]):
+        raw_rows.append({
+            "id": a["id"],
+            "userId": a["userId"],
+            "title": a["title"],
+            "photo_count": counts.get(a["id"], 0),
+        })
+
+    if len(albums) != 100:
+        print("FAIL: expected 100 albums, got %d" % len(albums))
+        return 1
+    if len(photos) != 5000:
+        print("FAIL: expected 5000 photos, got %d" % len(photos))
+        return 1
+    if len(counts) != 100:
+        print("FAIL: expected 100 distinct album ids with photos, got %d" % len(counts))
+        return 1
+    if len(set(counts.values())) != 1:
+        print("FAIL: photo_count not uniform, values=%s" % sorted(set(counts.values())))
+        return 1
+
+    # CSV: committed file parsed with DictReader -> all strings.
+    csv_rows = []
+    for r in raw_rows:
+        csv_rows.append({
+            "id": str(r["id"]),
+            "userId": str(r["userId"]),
+            "title": r["title"],
+            "photo_count": str(r["photo_count"]),
+        })
+    if read_csv_rows(CSV_PATH) != csv_rows:
+        print("FAIL: CSV does not match fresh extraction")
+        return 1
+
+    # JSON: committed file parsed -> ints for id/userId/photo_count.
+    if json.load(open(JSON_PATH, encoding="utf-8")) != raw_rows:
+        print("FAIL: JSON does not match fresh extraction")
+        return 1
+
+    print("OK: %d rows match the fresh extraction (uniform photo_count=50, %d photos)"
+          % (len(raw_rows), total))
+    return 0
+
+
+if __name__ == "__main__":
+    sys.exit(main())