re: the effect->package map, 103 of 137 - and eff_f0002 was a substring artefact

Enumerating eff_* names per .xpr across all 166 packages and matching the bound
names EXACTLY gives a real home for 103 of the 137, up from the 71 ptc_pack
alone accounted for. Only 36 packages carry an effect name at all, and two
dominate:

  Base.xpr                  53
  ptc_pack.xpr              46
  Stage_S28.xpr              2
  five rou_f001_wep_NN.xpr   1 each

So there are TWO shared effect libraries, not one - and ptc_pack.xpr is the only
*_pack bundle on the disc, so no third shared library is hiding. By digit-width:
3-digit 80 resolved of 110, 4-digit 23 of 27. The previous iteration's split
survives and sharpens - the four-digit series really does live outside ptc_pack
(that zero stands), and now we can say where: Base.xpr.

Correction to the previous commit. It reported eff_f0002 and eff_f0002_barn as
present in Base.xpr. Both were SUBSTRING artefacts: what the file actually holds
is eff_f0002_barnhaze, one longer resource name that grep -l eff_f0002 and
grep -l eff_f0002_barn each match inside. Neither bound name is there. This is
the corpus's own paid-for prefix lesson arriving from the other direction - last
time it was rot_n001 vs rot_n001_break with the stored name longer; here the
BOUND name was the prefix. The new map is exact-keyed and does not have this
failure mode, so the earlier positive is withdrawn.

34 names remain unlocated, dominated by a family the last pass did not single
out: eff_l### with 17 of the 34, then h 4, s 4, j 2, m 2, t 1, and four
four-digit names - eff_e0044, eff_f0002, eff_f0002_barn, eff_n0071.

Scope note worth keeping: the j 22 / t 14 clustering reported last time was the
residual against ptc_pack ALONE; against all packages those families are largely
accounted for and l is what is left. Both numbers are right for their own
population, which is exactly why a residual has to say what it was measured
against.

New artefact with its regenerator: tools/re-capture/effect_homes.py ->
docs/re/data/effect-homes.txt, which lists all 34 by name. All sixteen existing
artefacts byte-identical.

docs/re/BACKLOG.md

@@ -6707,3 +6707,31 @@ cluster on `j` (22) and `t` (14); `ptc_pack` holds just one `j` name, so
 🟡 **Not closed**: 66 of 137 bound effects still have no located home,
 `eff_n0071` included. ❔ Next: the `eff_j###` family and the four-digit series —
 not another disc-wide grep.
+
+---
+
+## ✅❌ 2026-08-28 — the effect→package map (103 of 137), and a substring correction
+
+Item (a). Enumerating `eff_*` **per `.xpr`** across all 166 packages and matching
+bound names **exactly** locates **103 of the 137**, up from 71. Only 36 packages
+carry an effect name; two dominate: **`Base.xpr` 53** and **`ptc_pack.xpr` 46**
+(then `Stage_S28.xpr` 2 and five `rou_f001_wep_NN.xpr` at 1 each).
+
+🔑 **Two shared effect libraries, not one** — and `ptc_pack.xpr` is the only
+`*_pack` bundle on the disc. By digit-width: **3-digit 80 of 110, 4-digit 23 of
+27**, so the previous iteration's split survives and sharpens — the four-digit
+series lives outside `ptc_pack`, in `Base.xpr`.
+
+❌ **Correction to the previous entry**: `eff_f0002` and `eff_f0002_barn` do
+**not** ship. `Base.xpr` contains **`eff_f0002_barnhaze`**, and both substring
+greps matched inside it. The corpus's paid-for prefix lesson arriving from the
+other direction — this time the *bound* name was a prefix of the *stored* one.
+
+🟡 **34 remain**, dominated by **`eff_l###` (17)**, then `h` 4, `s` 4, `j` 2,
+`m` 2, `t` 1, and four four-digit names including `eff_n0071`. ⚠️ Scope note: the
+`j` 22 / `t` 14 clustering reported last time was the residual against
+`ptc_pack` alone; against all packages `l` is what is left. **Say which
+population a residual is measured against.**
+
+New artefact: `tools/re-capture/effect_homes.py` → `docs/re/data/effect-homes.txt`
+(lists all 34 by name).