name the output pool restriction for what it restricts

It is no longer about reprocessing: any recipe with several output groups is
subject to it, and the plant is only the building that happens to have one
(REQ-MAT-OUTPUT-GROUP). REQ-LOCK-REPROCESSING-POOL becomes REQ-LOCK-OUTPUT-POOL.
Four citations, all in docs -- no code cites it.

Also corrects a line REQ-LOCK-IMPLICIT still carried from before smelters had a
recipe control: their recipes are not "never shown in any UI dropdown" any more,
they are simply never gated, so the dialog offers all of them.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01Ne3mejABZoLWKLh8fgpM3x

docs/balancing/rules.md

@@ -231,7 +231,7 @@ supporting different fleet doctrines feel structurally different to build.
   **reprocessing** (probabilistic higher intermediates, including the
   late-game input — the gamble that eventually becomes mandatory).
 - The reprocessing output pool renormalizes over implicitly unlocked items
-  (REQ-LOCK-REPROCESSING-POOL), so its output quality improves
+  (REQ-LOCK-OUTPUT-POOL), so its output quality improves
   automatically as the run progresses. **Rule:** weights are authored for
   the *fully unlocked* pool state; early-game behavior falls out of
   renormalization for free and needs no separate staging.

docs/requirements.md

@@ -152,7 +152,7 @@ Any ship, module, building, or assembler recipe id that appears in no unlock gro
 - REQ-BLD-MINER: **Miner** (2×2): The player selects which ore type it extracts. Each ore type corresponds to a `recipes.toml [[recipe]]` entry with `building = "miner"`, defining the output item and `duration_seconds`. Every asteroid tile is equivalent for mining — any miner can produce any ore type based solely on its selected recipe. Ore never depletes. Only implicitly unlocked ore-type recipes are available for selection (REQ-LOCK-UI-RECIPE).
 - REQ-BLD-SMELTER: **Smelter** (2×2): Converts ore or scrap into basic materials. Its recipe is selected as any other building's is, except that it also picks one for itself from the first material it is offered (REQ-BLD-AUTO-RECIPE). Inputs, outputs, and rates are defined in `recipes.toml [[recipe]]` entries with `building = "smelter"`.
 - REQ-BLD-ASSEMBLER: **Assembler** (3×3): The player selects a recipe from the config-defined crafting tree. Produces what that recipe produces (REQ-MAT-OUTPUT-GROUP) at the rate defined in the corresponding `recipes.toml [[recipe]]` entry with `building = "assembler"`. Only implicitly unlocked recipes are available for selection (REQ-LOCK-UI-RECIPE).
-- REQ-BLD-REPROCESSING: **Reprocessing Plant** (3×3): Consumes scrap per cycle and produces one of several possible higher-level intermediate products, picked at cycle start. It is the one building whose recipes carry **more than one output group** (REQ-MAT-OUTPUT-GROUP) — that, and nothing about the building itself, is what makes its yield random; its inputs, groups, weights and amounts are defined in `recipes.toml [[recipe]]` entries with `building = "reprocessing_plant"` like any other recipe's. The eligible groups are restricted to those whose items are implicitly unlocked (REQ-LOCK-REPROCESSING-POOL). Its output side follows the general rules with no exception: one buffer per item any group can produce (REQ-MAT-OUTPUT-BUFFER), and a cycle starts only when every group would fit (REQ-MAT-CYCLE) — which is also what denies the player a reroll by stalling the output belt. Like the Smelter it picks its recipe from the first material it is offered while none is set (REQ-BLD-AUTO-RECIPE).
+- REQ-BLD-REPROCESSING: **Reprocessing Plant** (3×3): Consumes scrap per cycle and produces one of several possible higher-level intermediate products, picked at cycle start. It is the one building whose recipes carry **more than one output group** (REQ-MAT-OUTPUT-GROUP) — that, and nothing about the building itself, is what makes its yield random; its inputs, groups, weights and amounts are defined in `recipes.toml [[recipe]]` entries with `building = "reprocessing_plant"` like any other recipe's. The eligible groups are restricted to those whose items are implicitly unlocked (REQ-LOCK-OUTPUT-POOL). Its output side follows the general rules with no exception: one buffer per item any group can produce (REQ-MAT-OUTPUT-BUFFER), and a cycle starts only when every group would fit (REQ-MAT-CYCLE) — which is also what denies the player a reroll by stalling the output belt. Like the Smelter it picks its recipe from the first material it is offered while none is set (REQ-BLD-AUTO-RECIPE).
 - REQ-BLD-AUTO-RECIPE: **Automatic recipe selection.** The Smelter and the Reprocessing Plant (REQ-BLD-SMELTER, REQ-BLD-REPROCESSING) are *auto-recipe buildings*. They carry a selected recipe and are configured exactly as a Miner or Assembler is — the same selection button and dialog (REQ-UI-SELECT-BUTTON), buffers sized for that one recipe alone (REQ-MAT-INPUT-BUFFER, REQ-MAT-OUTPUT-BUFFER), and the same pre-configuration on a construction site (REQ-BLD-SITE-CONFIG). They differ in one respect only:
   - **Selection while none is set.** When such a building has no recipe, the first material offered at any of its input ports that some recipe of its type consumes selects that recipe; the material is then accepted as normal. This holds for every intake path — a belt, splitter or tunnel exit at an input port, and a directly coupled producer (REQ-MAT-DIRECT-COUPLE) — because a building that accepts nothing would otherwise leave a coupled producer stuck at its port forever. The choice is deterministic: input ports are examined in order, and where several recipes of the type consume the offered material the first in config order wins.
   - **No further switching.** Once a recipe is set the building keeps it. It does not switch when its buffers run empty, nor when a material belonging to another of its recipes arrives — that material is simply not an accepted input, exactly as for any other building.
@@ -203,7 +203,7 @@ Any ship, module, building, or assembler recipe id that appears in no unlock gro
 - REQ-MAT-INPUT-BUFFER: Each building has one input buffer per required input material. Each per-material buffer holds up to twice that material's per-cycle requirement. When the player selects a new recipe or schematic, all items in all input buffers are cleared.
   - **Setting a configuration to the value it already holds is a no-op.** Selecting the recipe or schematic already set, or applying a ship layout identical to the one already configured, changes nothing: buffers are not cleared, an in-progress production cycle is not cancelled (REQ-BLD-SHIPYARD), and a construction site's progress and stored settings are untouched. This holds however the setting is applied — through the selection dialog (REQ-UI-SELECT-BUTTON), the layout configuration dialog (REQ-MOD-UI-DIALOG), a blueprint placement (REQ-UI-BLUEPRINT-PLACE), or a blueprint configuration transfer (REQ-UI-BLUEPRINT-TRANSFER). Only a setting that genuinely differs has effects.
 - REQ-MAT-OUTPUT-GROUP: **What a recipe produces.** A recipe's output is defined as one or more **output groups**, each carrying a probability weight and a list of item/amount pairs. One cycle produces the items of exactly **one** group, decided at cycle start (REQ-MAT-CYCLE); the items within that group are all produced together.
-  - A recipe with a **single group** always produces it. There is nothing to choose, so no weight is consulted, no randomness is involved, and no eligibility is tested (REQ-LOCK-REPROCESSING-POOL). This is the ordinary recipe, and the shape of all but the reprocessing ones.
+  - A recipe with a **single group** always produces it. There is nothing to choose, so no weight is consulted, no randomness is involved, and no eligibility is tested (REQ-LOCK-OUTPUT-POOL). This is the ordinary recipe, and the shape of all but the reprocessing ones.
   - A recipe with **several groups** picks one by weight at cycle start. Weights are normalized at load time; their sum does not need to equal 1.
   - There is no separate deterministic and probabilistic kind of recipe: the two are one shape with one group and with several. Every rule about outputs is written over groups, so none of them needs to distinguish the two cases — or which building runs the recipe.
   - **Config shape.** A group is a `[[recipe.output_group]]` entry with `probability` and `items = [{item, amount}, ...]`. The single-group case may instead be written as `outputs = [{item, amount}, ...]`, which means exactly one group holding those items. A recipe uses one form or the other; both present fails config load.
@@ -395,9 +395,9 @@ Any ship, module, building, or assembler recipe id that appears in no unlock gro
   1. Start with the union of: (a) all item types listed in `materials` across all currently unlocked ship schematics and all currently unlocked module schematics, and (b) the output item types of every assembler recipe that is currently **explicitly available** — that is, either flagged `unlocked_at_start` in `recipes.toml`, or granted by an unlock group that has been awarded (REQ-LOCK-EXPLICIT).
   2. For each item type in the current set: for every recipe (miner, smelter, or assembler) that produces it — skipping any assembler recipe that is granted by an unlock group whose group has not yet been awarded — add each of that recipe's input item types to the set. If the recipe is a miner recipe, or an assembler recipe that is not granted by any unlock group, mark it as implicitly unlocked. Assembler recipes that are explicitly available (flagged `unlocked_at_start`, or granted by an awarded unlock group) are available in the assembler recipe-selection dialog by virtue of REQ-LOCK-EXPLICIT; their inputs are also added to the implicit set in this step.
   3. Repeat step 2 until no new item types are added.
-  Item types and miner/assembler recipes not reached by this process (and not explicitly unlocked) are locked. Smelter recipes participate in the traversal to propagate unlocking to their inputs but are never themselves shown in any UI dropdown.
+  Item types and miner/assembler recipes not reached by this process (and not explicitly unlocked) are locked. Smelter recipes participate in the traversal to propagate unlocking to their inputs but are never themselves gated by it: they are not granted by unlock groups either (REQ-LOCK-EXPLICIT), so a Smelter's dialog offers all of them once the building is unlocked (REQ-LOCK-UI-RECIPE, REQ-BLD-AUTO-RECIPE).
 
-- REQ-LOCK-REPROCESSING-POOL: **The choice between output groups is restricted to what the player can use.** Where a recipe has several output groups (REQ-MAT-OUTPUT-GROUP), only groups whose items are **all** currently implicitly unlocked (REQ-LOCK-IMPLICIT) are eligible; a group holding any locked item is dropped whole, since its items are produced together and taking it would hand the player a locked one. Weights are renormalized over the eligible groups, and if none remains the cycle cannot start.
+- REQ-LOCK-OUTPUT-POOL: **The choice between output groups is restricted to what the player can use.** Where a recipe has several output groups (REQ-MAT-OUTPUT-GROUP), only groups whose items are **all** currently implicitly unlocked (REQ-LOCK-IMPLICIT) are eligible; a group holding any locked item is dropped whole, since its items are produced together and taking it would hand the player a locked one. Weights are renormalized over the eligible groups, and if none remains the cycle cannot start.
 
   The restriction is on the **choice**, not on production: a recipe with a single group has no choice to restrict and is never tested for eligibility. This distinction is load-bearing rather than an optimization. Implicit unlocking is derived from demand — an item becomes unlocked because something the player can build needs it (REQ-LOCK-IMPLICIT) — so an ordinary recipe's output can be perfectly producible while nothing yet calls for it. Testing eligibility there would not gate a drop, it would stop the building producing at all. In practice this governs the Reprocessing Plant, the only building whose recipes have several groups (REQ-BLD-REPROCESSING).