docs(media): the 2026-11-04 purge, and the gate that proves a hold is safe to delete

The duplicate-prune, TV-duplicate, Ghibli and promo-clip holds went out of the
array trash on Frank's word: ~1.2 TB back. This replaces the three "purge pending
Frank's word" rows with what happened.

Two procedures the page did not carry:

- The purge gate. `REAL: 0` in both databases only says no row points at a moved
  path; it says nothing about whether the film survived. Every held file needs a
  same-work carrier in the live library at >= its size, re-derived at purge time,
  because the relayout renames folders AND keeper files, accents defeat ASCII
  matching (Nausicaä), and a carrier is usually another container at another
  size. That supersedes the 2026-11-01 "re-verify by size" law, which is exactly
  the test that reports survivors as lost.
- The purge mechanics. The repo purger acts on a root's own .AGENTTRASH and
  nothing else, so a partial purge is staged into a scratch root while the
  unapproved buckets sit parked at the array root as .HOLD-<date>-*.

./tests/run.sh: 824 assertions, all pass.

serverAppConfigs-docs/Dankserver/Media Duplicate Prune.md

@@ -179,21 +179,57 @@ keeper is missing — either one drops the whole group rather than half-applying
   era, not this pass — read the mtimes before blaming the prune.
 - The 2026-11-01 pass held 226 files (~1.1 TiB) in
   `/mnt/entropy/.AGENTTRASH/20261101-duplicate-prune`, journals
-  `dup-prune-exact.jsonl` and `dup-prune-similar.jsonl`. Purge pending Frank's word.
+  `dup-prune-exact.jsonl` and `dup-prune-similar.jsonl`.
-- The 2026-11-02 TV pass holds 220 files (54 GiB) in
+- The 2026-11-02 TV pass held 220 files (54 GiB) in
   `/mnt/entropy/.AGENTTRASH/20261102-tv-duplicates` — plan `tv-dupes-plan.tsv`,
   journal `tv-dupes.jsonl`, 220 moves / 16 hold folders / 7 husks swept — and the
-  same day's TVShows detritus pass holds 109 files (552 KiB) in
+  same day's TVShows detritus pass staged 109 files (552 KiB) in
   `/mnt/entropy/.AGENTTRASH/20261102-tvshows-detritus` with plan
-  `tvshows-detritus-plan.tsv` and journal `tvshows-detritus.jsonl`. Both purges
+  `tvshows-detritus-plan.tsv` and journal `tvshows-detritus.jsonl`. All four
-  pending Frank's word, beside the 2026-11-01 hold above. All four journals and
+  journals and plans live at the `entropy` root, not `/tmp`.
-  plans live at the `entropy` root, not `/tmp`.
+- **Purged 2026-11-04, on Frank's word, after the gate below:** the duplicate
-- **Re-verify each survivor by size, not by the recorded path, before purging.**
+  prune, the TV duplicate pass, the Ghibli duplicates (6 files — both `Nausicaä`
-  Detection artifacts and plans key on paths, and a folder renamed by an
+  copies among them) and the 2026-11-04 promo-clip hold left the array trash,
-  interactive session ([[Entropy Volume]], *Write doors*) makes its keeper look
+  ~1.2 TB freed (the array went 218 GB → 1.4 TB available). The journals survive as
-  deleted while it sits untouched under the new name. The 2026-11-01 audit hit
+  the only record of where a purged file came from; rollback after a purge is
-  three such groups: every keeper was present, same bytes, different folder. A
+  impossible, which is why the gate runs first.
-  purge decided from the plan's paths alone would have reported survivors gone.
+
+### The purge gate: a carrier for every held file
+
+`REAL: 0` in both databases says only that no row points at a moved path; it says
+nothing about whether the film survived. So a purge waits on a stronger proof:
+**every held file has a same-work carrier in the live library at >= its size,
+re-derived at purge time**, never copied from the plan. The 2026-11-04 purge re-found
+all 452 held files this way; the first pass of the gate could not place 142 of them,
+and every one of those was a matcher gap, not a lost film. What the re-derivation has
+to absorb:
+
+- **The layout moves under the plan.** The relayout renames folders to
+  `Title (YYYY)` and `[tvdbid-N]/Season N` and renames the keeper files too, so the
+  paths *and* the sizes a plan recorded no longer describe the library. Keys are work
+  identity — normalized title+year for a film, `(S,E)` for a TV pack — never a path.
+- **Fold accents, then compare.** The library holds `Nausicaä`; a plan, a
+  `find -ipath "*Nausicaa*"`, and an ASCII substring search all miss it. NFKD-fold and
+  drop combining marks, or a real keeper reads absent for two rounds and the file
+  beside it starts to look like an orphan.
+- **The carrier is often another container, and usually larger.** A held `.mp4` can be
+  kept as the sibling `.mkv`; keep-larger means the keeper is frequently far bigger (a
+  377 MB held episode matched a 501 MB keeper; a 1.6 GiB film stands beside a 34 GiB
+  BDRemux of itself in another folder). "Same folder, same bytes" reports survivors as
+  lost — it is the wrong test.
+- **An exact twin can sit in a sibling folder**, so "no same-size file in the folder"
+  needs an array-wide name search before it means anything.
+
+### Running the purge
+
+`scripts/purge-agenttrash.sh` is the only door — never `rm`. It acts on exactly one
+object: a root's own `.AGENTTRASH`. A partial purge is therefore **staged, not
+filtered**: move the approved buckets into a scratch root
+(`.PURGE-<date>/.AGENTTRASH/`) and point the purger at that root, and park anything
+not approved at the array root as `.HOLD-<date>-*`, out of its reach. Dry-run first —
+the plan must print exactly one `plan empty` row, and it is the same row `--execute`
+acts on — and send `--log` into `.media-campaign/`, because `/tmp` is not a record.
+Then read `df`: a purge is the only media act that moves the free-space number.
 
 ## After the pass