examples: anime library sorter + pure-Lua Anitomy parser

Add a worked nautd scripting example that files each anime episode into a
media-server-friendly library the moment its file finishes verifying:

    <SORTED_ROOT>/<Title>/Season NN/<Title> - SNNENN.<ext>

- examples/anitomy.lua: a compact, dependency-free reimplementation of Anitomy
  (title/season/episode/release-group/resolution/year) in pure Lua — no
  require/io/os, so it embeds in the sandbox.
- examples/anime_sort.lua: on_file_complete hook that parses the filename and
  calls naut.move_file(); the embedded parser is a verbatim copy of anitomy.lua.
- examples/test_anitomy.lua, test_anime_sort.lua: parser battery + end-to-end
  path-building test with an embedded-vs-module drift guard. Wired into ctest as
  example_anitomy / example_anime_sort when a lua interpreter is present.
- docs: examples/README.md plus pointers from README and docs/scripting.md.

Verified end to end against a live nautd: file_complete -> move_file -> on-disk
relocate into the sorted tree.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

examples/test_anime_sort.lua

@@ -0,0 +1,88 @@
+-- Tests anime_sort.lua end to end (stubbing the `naut` host API) and verifies
+-- its embedded parser still matches examples/anitomy.lua.
+-- Run: lua examples/test_anime_sort.lua
+local dir = arg[0]:match("^(.*/)") or "./"
+package.path = dir .. "?.lua;" .. package.path
+local ref = require("anitomy")
+
+-- stub the host API the script calls, and silence its prints
+local captured
+_G.naut = { move_file = function(tid, idx, dest) captured = dest end }
+local realprint = print
+_G.print = function() end
+
+dofile(dir .. "anime_sort.lua")   -- defines on_file_complete + _G.anime_sort
+
+_G.print = realprint
+
+local fails = 0
+local function fire(path)
+    captured = nil
+    on_file_complete({ torrent_id = 1, index = 0, path = path })
+    return captured
+end
+local function expect(path, want_dest)
+    local got = fire(path)
+    if got ~= want_dest then
+        fails = fails + 1
+        realprint("FAIL  " .. path)
+        realprint("        got:  " .. tostring(got))
+        realprint("        want: " .. tostring(want_dest))
+    else
+        realprint("ok    " .. path)
+    end
+end
+
+-- episodes
+expect("/downloads/1/[HorribleSubs] Boku no Hero Academia - 12 [1080p].mkv",
+       "/sorted/Boku no Hero Academia/Season 01/Boku no Hero Academia - S01E12.mkv")
+expect("/downloads/2/[Group] Attack on Titan S04E28 [BD 1080p HEVC].mkv",
+       "/sorted/Attack on Titan/Season 04/Attack on Titan - S04E28.mkv")
+expect("/dl/[Commie] Steins;Gate 0 - 12 [BD 1080p].mkv",
+       "/sorted/Steins;Gate 0/Season 01/Steins;Gate 0 - S01E12.mkv")
+expect("Demon.Slayer.Kimetsu.no.Yaiba.S03E11.1080p.mkv",
+       "/sorted/Demon Slayer Kimetsu no Yaiba/Season 03/Demon Slayer Kimetsu no Yaiba - S03E11.mkv")
+expect("/x/[Erai-raws] Jujutsu Kaisen 2nd Season - 17 [1080p].mkv",
+       "/sorted/Jujutsu Kaisen/Season 02/Jujutsu Kaisen - S02E17.mkv")
+
+-- movies (no episode)
+expect("/m/[Group] A Silent Voice [BD 1080p FLAC].mkv",
+       "/sorted/A Silent Voice/A Silent Voice.mkv")
+expect("/m/Spirited.Away.2001.1080p.BluRay.x264.mkv",
+       "/sorted/Spirited Away/Spirited Away (2001).mkv")
+
+-- non-video file must be skipped (no move queued)
+do
+    local got = fire("/d/[Group] Some Show - 01 [1080p].ass")
+    if got ~= nil then
+        fails = fails + 1
+        realprint("FAIL  non-video should be skipped, got: " .. tostring(got))
+    else
+        realprint("ok    non-video skipped")
+    end
+end
+
+-- drift guard: embedded parser must agree with anitomy.lua
+local embedded = _G.anime_sort.anitomy
+local drift = 0
+for _, name in ipairs({
+    "[HorribleSubs] Boku no Hero Academia - 12 [1080p].mkv",
+    "[Group] Attack on Titan S04E28 [BD 1080p HEVC].mkv",
+    "One.Piece.S01E1071.1080p.WEB.x264.mkv",
+    "Spirited.Away.2001.1080p.BluRay.x264.mkv",
+    "[Commie] Steins;Gate 0 - 12 [BD 1080p].mkv",
+}) do
+    local a, b = ref.parse(name), embedded.parse(name)
+    for _, k in ipairs({ "title", "season", "episode", "year", "episode_end" }) do
+        if a[k] ~= b[k] then
+            drift = drift + 1
+            realprint(("DRIFT %s field %s: anitomy=%s embedded=%s")
+                :format(name, k, tostring(a[k]), tostring(b[k])))
+        end
+    end
+end
+if drift == 0 then realprint("ok    embedded parser matches anitomy.lua")
+else fails = fails + drift end
+
+if fails == 0 then realprint("\nALL PASS"); os.exit(0)
+else realprint("\n" .. fails .. " FAILED"); os.exit(1) end