chore(plugins): add [integrity] SHA-256 hashes for all hook scripts

The daemon's `manifest_missing_integrity_hooks` check (#3804) hard-fails
any registry install whose plugin.toml declares hooks but lacks an
[integrity] entry for each one. All 11 plugins under plugins/ had the
[hooks] table but were missing [integrity], so `librefang plugin install
<name>` would error after download with "missing [integrity] hashes for
hook script(s): ...".

Compute and pin SHA-256 over each `hooks/*.py` under every plugin dir.
The mempalace-indexer entries were already present and are unchanged
(reordered alphabetically by the regenerator).

Verified each plugin.toml still parses (Python tomllib).

plugins/user-profile/plugin.toml

@@ -35,3 +35,7 @@ description = "Perfilado persistente del usuario a partir de patrones de convers
 [i18n.fr]
 name = "Profil utilisateur"
 description = "Profilage persistant basé sur les motifs de conversation pour des réponses personnalisées."
+
+[integrity]
+"hooks/after_turn.py" = "e1e12c2e6a3e32e2c26b4184836229f7f6cb32b0e14fcca82496354ff3b36f73"
+"hooks/ingest.py" = "28ae3b2435b6e46ef7bfd71b913f2e8c96d1a89120b48eb4cd54ceaefc18501b"