Advance Bubble export: corpus walk and ADR-0004 sample tree

Add corpus exporter (session + ES capture), record 71 spaces / 109 articles
and local reichelag markdown tree with visuals. Redacted progress only in git.

docs/migration/README.md

@@ -6,6 +6,7 @@ CSOC-WP-0001-T02/T04 home for Bubble → rebuild mapping and rehearsal notes.
 |-----|--------|
 | `bubble-auth-and-export.md` | **Safe read access for agents** (session file; no secrets in chat) |
 | `field-map-from-session-2026-08-13.md` | **Field map from live session export** (article/space/user) |
+| `export-progress-2026-08-13.md` | Corpus counts + sample tree path (no private bodies) |
 | `schema-mapping-sketch-2026-08-12.md` | Provisional mapping (supersede with field map) |
 | *(later)* field-level map | After authenticated dump |
 | *(later)* rehearsal log | Import of one space to thin git tree (ADR-0004) |

docs/migration/export-progress-2026-08-13.md

@@ -0,0 +1,82 @@
+# Export progress — 2026-08-13
+
+| Field | Value |
+|-------|--------|
+| Workplan | CSOC-WP-0001-T02 |
+| Auth | Local Playwright session (XDG; not in git) |
+| Local corpus | `~/.config/coulomb-social/auth/exports/corpus-202608131015057/` |
+
+## Results (no content bodies in git)
+
+| Metric | Count |
+|--------|------:|
+| Spaces | 71 |
+| Articles (unique) | 109 |
+| Spaces with ≥1 article in dump | 70 |
+| Sample tree pages | 30 (29 articles + index) |
+| Sample visuals downloaded | 29 (~1.6 MB) |
+
+### Articles per space (histogram)
+
+| Articles in space | # spaces |
+|------------------:|---------:|
+| 0 | 1 |
+| 1 | 62 |
+| 2 | 4 |
+| 3 | 2 |
+| 4 | 1 |
+| 29 | 1 (sample) |
+
+Most spaces are thin (one home/article). One dense space was used as the
+**rehearsal tree** (local only).
+
+## Sample tree shape (ADR-0004)
+
+```text
+trees/<space-slug>/
+  pages/
+    index.md                 # space landing
+    <article-slug>.md        # title/abstractor/visual + body
+  assets/
+    <article-slug>-visual.*  # logo_image downloads
+```
+
+Frontmatter keys (per page):
+
+```yaml
+id: bubble:<id>
+title: "…"           # nomer_text
+abstractor: "…"      # abstractor_text
+visual: "assets/…"   # logo_image → local file
+space: "<slug>"
+bubble_type: article
+archived: false
+parent: ""           # context_custom_article when set
+```
+
+## Methods used
+
+1. Seed from first session network capture (ES msearch/mget responses).  
+2. UI walk: open named spaces on `/vw_spaces` then `/vw_pages` + scroll (Bubble ES
+   request bodies are **encrypted** — cannot craft free-form API queries).  
+3. Emit JSON corpus + markdown tree under XDG only.
+
+## Limits
+
+- Article coverage beyond the “active” space is incomplete (many spaces only
+  have 1 article in the dump; more may exist server-side).  
+- Space **display title** is not a first-class field on `custom.space` (only
+  `Slug`); UI names come from related articles / presentation.  
+- Dense sample content is **private** — tree stays out of git.
+
+## Next
+
+1. Optional: longer crawl / pagination to fill more per-space articles.  
+2. **T04 rehearsal:** PageOps import of local tree into app content dir (CSOC-WP-0006).  
+3. Member → NetKingdom identity mapping for membership lists (no passwords).
+
+## Related
+
+- `docs/migration/field-map-from-session-2026-08-13.md`
+- `docs/migration/bubble-auth-and-export.md`
+- ADR-0003, ADR-0004

docs/migration/field-map-from-session-2026-08-13.md

@@ -140,9 +140,9 @@ archived: false
 
 ## Next actions
 
-1. Extend exporter to walk **all spaces** the user can access and dump article JSON redacted/normalized into a private corpus.  
-2. Download visuals for sample space.  
-3. Emit one space as ADR-0004 tree (rehearsal dry-run for T04).  
+1. ~~Extend exporter / sample tree~~ — see `export-progress-2026-08-13.md` + `scripts/export-bubble-corpus.mjs`.  
+2. Optional: deeper crawl for spaces with only 1 article if more body pages exist.  
+3. **T04:** import local sample tree via PageOps (CSOC-WP-0006).  
 4. Keep raw export **only** under XDG auth dir.
 
 ## Privacy