docs+tool: locate & extract world factory production-line recipes

The fixed single-recipe world structures (conveyors, e.g. 1 Raw Aurogen
Crystal -> 10 Energy Rods) are a separate mechanic from workbench recipes.
Document where they live and how to read them, with a reproducible extractor.

- docs/PRODUCTION_LINES.md: the 'where to find it' record — ECS classes
  (ProductionLineRecipeComponent -> CraftingRecipe), the epb_assets_all
  game_conveyor_*_epb prefabs, EntityBlueprint/Odin serialization, the
  extraction path, and the open energy_grid_*/island-placement lead.
- bundle/extract_production_lines.py: UnityPy + odin_read extractor ->
  extracted/production_lines.json (14 conveyor recipes).
- BUNDLES.md: add production_lines.json to the data-source map.

docs/PRODUCTION_LINES.md

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+# World factory "production lines" (conveyors) — where to find them
+
+The game has **fixed single-recipe world structures** — item conveyors that run *one*
+recipe (e.g. **1 Raw Aurogen Crystal → 10 Energy Rods**). These are a separate mechanic
+from the player **workbench** recipes (which live in `extracted/crafting_recipes.json`,
+sourced from `CraftingRecipeBundle` assets). This note records **where they live** so the
+data can be re-derived after a game update.
+
+## The mechanic
+
+In code it's a *"Factory Production Line"*. It's an Entitas ECS feature, namespace
+`Hologryph.Sand.Shared.Game.Features.Crafting` (see `il2cpp/dump.cs`):
+
+| Class | Holds |
+|---|---|
+| `ProductionLineComponent` | `int inputEntityIndex`, `int outputEntityIndex` |
+| `ProductionLineRecipeComponent` | `CraftingRecipe recipe`  ← the recipe |
+| `ProductionLineInputDataComponent` / `…OutputDataComponent` | `bool isLargeItem{Input,Output}` |
+| `CraftingRecipe` | `CraftingIngredient[] inputIngredients`, `CraftingIngredient[] outputIngredients`, `float craftingTimeSeconds` |
+| `CraftingIngredient` | `string itemId`, `int amount` |
+
+Note `CraftingRecipe` / `CraftingIngredient` are the **same types** the workbench uses —
+only the container differs (a workbench holds `List<CraftingRecipeBundle> recipeBundles`;
+a production line holds a single `CraftingRecipe` on the entity).
+
+## Where the data lives
+
+- **Bundle:** `epb_assets_all.bundle` (reachable via the `bundles/` symlink).
+- **Prefabs:** `game_conveyor_*_epb.prefab`, under
+  `Assets/Content/Game/game_conveyor/...`. 14 carry a real recipe; the
+  `game_conveyor_base*` ones are template/test conversions (cf. `TestRecipesBundle`).
+- **Serialization:** each prefab GameObject (`m_Name = game_conveyor_<x>_epb`) has two
+  components — a `Transform` and a `MonoBehaviour` whose script is **`EntityBlueprint`**.
+  `EntityBlueprint : SerializedMonoBehaviour` (Sirenix Odin), so the component data —
+  including the `CraftingRecipe` — is in its **Odin-serialized
+  `serializationData.SerializedBytes`**, not in plain typetree fields. (Same situation as
+  the loot tables — see [TASK.md](TASK.md) / `extract_loot.py`.)
+
+### Extraction path (how to read it)
+
+`UnityPy` (with an IL2CPP `TypeTreeGenerator` over `GameAssembly.dll` +
+`global-metadata.dat`) reads the `EntityBlueprint` MonoBehaviour → pull
+`serializationData.SerializedBytes` → `bundle/odin_read.py` parses the Odin binary →
+walk the tree for the node with `inputIngredients` / `outputIngredients`.
+
+```bash
+venv/bin/python bundle/extract_production_lines.py   # -> extracted/production_lines.json
+```
+
+Key item ids seen here: `item_crystalHandles` = *Raw Aurogen Crystal*,
+`item_energyBar` = *NZ Mk2 Energy Rod*, `item_blackBox` = *Black Box*,
+`item_resourceCoralPiece` = *Coral Chunk*. Resolve any id → display name via
+`extracted/items_registry.json` / `extracted/item_names.json` (built from
+`CheatItemDefinitionsData`).
+
+## Island placement — open lead
+
+Which factory/island runs which conveyor is grouped by the
+`energy_grid_*_epb.prefab` blueprints in the same bundle:
+`Wunderinsel`, `Kaiserplatz`, `DeusExMachine`, `Factorio`, `LittleFactory1-3`,
+`LittleFactoryArmory1-3`, `TestFactory`. The **`…Armory`** groups are the likely
+**Sprengstofffabrik** (explosives factory) host for the explosive / grenade / rocket /
+cannon conveyors.
+
+**Not yet resolved:** an `energy_grid_*` blueprint's Odin data references its conveyors by
+**entity reference, not item-id string** (a string scan of its serialized bytes finds no
+`game_conveyor_*` / `item_*` ids). So mapping recipe → specific island needs the **island
+prefab placements** in `islands_assets_all.bundle` (the `island_*` / fort / `loc_event_*`
+prefabs, where `Sprengstofffabrik` is an i2 `Toponyms/` name), not the conveyor or
+energy_grid EPBs alone. That linkage is the next step if island attribution is wanted.