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_anitomy.lua

@@ -0,0 +1,75 @@
+-- Battery test for anitomy.lua. Run: lua examples/test_anitomy.lua
+package.path = (arg[0]:match("^(.*/)") or "./") .. "?.lua;" .. package.path
+local anitomy = require("anitomy")
+
+local fails = 0
+local function check(name, want)
+    local p = anitomy.parse(name)
+    local ok = true
+    local why = {}
+    for _, k in ipairs({ "title", "season", "episode" }) do
+        if want[k] ~= nil and p[k] ~= want[k] then
+            ok = false
+            why[#why + 1] = string.format("%s: got %s want %s",
+                k, tostring(p[k]), tostring(want[k]))
+        end
+    end
+    if not ok then
+        fails = fails + 1
+        print("FAIL  " .. name)
+        for _, w in ipairs(why) do print("        " .. w) end
+    else
+        print(string.format("ok    %-58s -> %s / S%s / E%s",
+            name, p.title, tostring(p.season), tostring(p.episode)))
+    end
+end
+
+-- title, season, episode expectations
+check("[HorribleSubs] Boku no Hero Academia - 12 [1080p].mkv",
+      { title = "Boku no Hero Academia", season = 1, episode = 12 })
+check("[SubsPlease] Spy x Family - 05 (1080p) [A1B2C3D4].mkv",
+      { title = "Spy x Family", season = 1, episode = 5 })
+check("[Group] Attack on Titan S04E28 [BD 1080p HEVC].mkv",
+      { title = "Attack on Titan", season = 4, episode = 28 })
+check("Kaguya-sama wa Kokurasetai S2 - 03 [720p].mkv",
+      { title = "Kaguya-sama wa Kokurasetai", season = 2, episode = 3 })
+check("[Erai-raws] Jujutsu Kaisen 2nd Season - 17 [1080p][Multiple Subtitle].mkv",
+      { title = "Jujutsu Kaisen", season = 2, episode = 17 })
+check("One.Piece.S01E1071.1080p.WEB.x264.mkv",
+      { title = "One Piece", season = 1, episode = 1071 })
+check("Anime_Name_-_01v2_[BD][720p].mkv",
+      { title = "Anime Name", season = 1, episode = 1 })
+check("[Judas] Chainsaw Man - 08v2 [1080p][HEVC x265 10bit].mkv",
+      { title = "Chainsaw Man", season = 1, episode = 8 })
+check("Mob Psycho 100 II - 05 [1080p].mkv",
+      { title = "Mob Psycho 100 II", season = 1, episode = 5 })
+check("[Commie] Steins;Gate 0 - 12 [BD 1080p].mkv",
+      { title = "Steins;Gate 0", season = 1, episode = 12 })
+check("[Group] Re Zero kara Hajimeru Isekai Seikatsu - Episode 25 [1080p].mkv",
+      { title = "Re Zero kara Hajimeru Isekai Seikatsu", season = 1, episode = 25 })
+check("Naruto Shippuuden - 500 [720p].mkv",
+      { title = "Naruto Shippuuden", season = 1, episode = 500 })
+check("[Group] Bleach - Season 2 - 14 [1080p].mkv",
+      { title = "Bleach", season = 2, episode = 14 })
+check("Demon.Slayer.Kimetsu.no.Yaiba.S03E11.1080p.mkv",
+      { title = "Demon Slayer Kimetsu no Yaiba", season = 3, episode = 11 })
+check("[Doki] K-On! - 01 (1280x720 Hi10P AAC) [12345678].mkv",
+      { title = "K-On!", season = 1, episode = 1 })
+check("[Group] Vinland Saga S2 - 24 END [1080p].mkv",
+      { title = "Vinland Saga", season = 2, episode = 24 })
+check("Frieren - 28 [Multi Sub] [1080p].mkv",
+      { title = "Frieren", season = 1, episode = 28 })
+
+-- movie / no-episode cases: episode must be nil
+check("[Group] A Silent Voice [BD 1080p FLAC].mkv",
+      { title = "A Silent Voice", episode = nil })
+check("Spirited.Away.2001.1080p.BluRay.x264.mkv",
+      { title = "Spirited Away", episode = nil })
+
+if fails == 0 then
+    print("\nALL PASS")
+    os.exit(0)
+else
+    print("\n" .. fails .. " FAILED")
+    os.exit(1)
+end