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/mempalace-indexer/plugin.toml

@@ -116,11 +116,10 @@ description = "Prune drawers older than this many days when running hooks/prune.
 # ---------------------------------------------------------------------------
 
 [integrity]
-"hooks/ingest.py" = "621b17f2d0afbd6142a49963fb57187a500cfeac057c13cb80961b6222bd03e2"
 "hooks/after_turn.py" = "1c5bcdade4ca0d785878d60910105208fcff38f74872426ee821363ce5bf9811"
+"hooks/ingest.py" = "621b17f2d0afbd6142a49963fb57187a500cfeac057c13cb80961b6222bd03e2"
 "hooks/prune.py" = "2dceeb9bb0d0b7ee224291bfce600f629f38b4a853cd437774d9b66ef226838d"
 
-
 [i18n.zh]
 name = "MemPalace 索引器"
 description = "自动把对话索引进 MemPalace 并召回相关记忆。无需 API key、不依赖云端。"