Add comprehensive design and specification documentation (#1)

* Write the Unreal documentation set: design, steps, ideas, decisions and specs

Rewrites the design and engineering docs of the two earlier Unity projects
(Adventurer Guild, Project Malleable) for an Unreal Engine 5 prototype that
builds and proves three things in order: a movement controller, fighting and
crafting. Neither earlier core loop is carried; their ideas are catalogued as
features with what each needs.

- Docs/Design.md: the human summary (pillars, fixed decisions, glossary)
- Docs/Steps.md: a ladder of fifteen proofs, the first six in full
- Docs/Ideas.md: salvaged ideas from both projects, none scheduled
- Docs/Decisions.md: D-01..D-36, open decisions OD-01..OD-08, deferrals
- Docs/Spec/: notation, Architecture, Movement, Interaction, Combat,
  Crafting, Networking, Telemetry, UI, written as Unreal C++ skeletons
- CLAUDE.md and README.md for the repository


* Add the stat block: one attribute set on every body, every influence an effect

Every body (player, enemy, NPC) carries the same UStatBlockAttributeSet, and
every outside influence on it is a gameplay effect: base values, buffs,
debuffs, ground surfaces, carried weight, gear, being downed. Counters are
tags and attributes on the receiver: immunity blocks by tag, resistance
scales by attribute, cleanse removes by tag. Same status from several
sources: strongest wins; different statuses multiply.

- Docs/Spec/Stats.md: the block, effects and their five sources (abilities,
  areas, surfaces, items, the world), stacking, counters, readers, tests
- Movement: the movement component's tagged speed-multiplier map is removed;
  speed is tuning times the MoveSpeed attribute; the ground surface trace
  turns mud into an effect; the gym gets mud and ice patches
- Combat: the attribute set moves to Stats; enemies and kits carry
  FStatBlockDefaults; the funnel reads MagicResist and Immune.Damage tags;
  taunt and mark are statuses
- Interaction: carried weight is GE_Encumbered against CarryCapacity
- Crafting: class bonuses are the WorkSpeed and WorkQuality attributes;
  enchantments may grant a holder effect
- Steps: step 5 builds the block with mud, a volume and an immunity
- Decisions D-37 and D-38; design summary, CLAUDE.md, indexes, worklog

Docs/Ideas.md

@@ -0,0 +1,172 @@
+# Ideas
+
+The two earlier projects, Adventurer Guild and Project Malleable, each designed a whole game around a core loop.
+This project keeps neither loop. It keeps the ideas, reshaped as features a world could hold rather than as the
+thing the game is about, and it keeps them here rather than in the specs so that none of them can be smuggled into
+a step as if it were already decided.
+
+Each entry says what the idea is, which mechanism is worth keeping, what it would need, and what it must not
+break. "Adopted" means the idea already lives in a spec. Nothing here is scheduled.
+
+## From Adventurer Guild
+
+### Contracts and the board
+
+Take a parchment off a wall, go and do it, come back and have it stamped. The mechanism worth keeping is the
+**stamp**: a ritual at the end of a job where the value is counted out in front of everyone, which is a better
+stopping point than a results screen because it gives a group a shared moment. Contracts as data (a target, a
+count, a reward, a standing requirement) and progress reported through one funnel from combat kills and item
+deliveries. Needs: a place to put the board, a reason to want the reward. Must not: replace playing with
+fetching; a contract is a reason to go somewhere, not the game.
+
+### The cart
+
+A physical, pushable container that carries the haul out. Tips, spills a fraction, gets righted. Pushed from the
+handles by taking them (an interaction), which routes movement input into the cart. The mechanism worth keeping
+is **hauling as a physical problem**: what you bring back is what fits and what you managed not to lose. Needs:
+somewhere to haul from and to; the physics of a pushed body on a server. Must not: be the only way to carry
+things; hands and (later) containers come first.
+
+### Grief verbs and the recoverability contract
+
+Shove, take from the cart, heal-launch, tip the cart. **Adopted as a rule** in [Combat.md](Spec/Combat.md): any
+verb that lets one player inconvenience another must have a recovery that takes less time than the verb did, and
+none may down, kill or permanently deprive. Every such verb emits `grief_action`. The verbs themselves arrive with
+the systems they act on.
+
+### Down, revive, bleed-out, wipe
+
+**Adopted whole** in [Combat.md](Spec/Combat.md).
+
+### Seeded generation
+
+A dungeon generated from a seed on every peer, byte-identical, so the server replicates eight bytes instead of
+megabytes. The determinism rules (own random stream, integer grid, ordered collections, no physics, no time), a
+critical path the cart can traverse, side branches that split the party, a shortcut door that only opens from the
+deep side, rooms as one-cell tiles in folders, typed spawn anchors with always/chance/budget rules, weighted
+pools, and an append-only pass that guarantees a contract's target exists. The mechanism worth keeping is all of
+it; it is the most worked-through part of the earlier project. Needs: a reason to have instanced places.
+Must not: assume one instance per server or that generation runs on the client only; both hold in the earlier
+design and both survive the move.
+
+### Party-size scaling
+
+Sublinear enemy budget (1.0, 1.75, 2.4, 3.0) and role relaxation below three players. **Adopted as a reserved
+rule** in [Combat.md](Spec/Combat.md), applied to a count for now.
+
+### Reputation, tiers, zones, upgrades
+
+Standing that gates content, tiers that pay more, an upgrade bench where gold buys modifiers that combat pulls
+by name (`GetModifier("cart.capacity")`), and the cross-class gear rule. The pull direction is the mechanism:
+combat asks for its numbers, progression never pushes into combat. The signature guardrail is **adopted** as the
+`bSignature` flag. Needs: a currency, a reason to spend. Must not: become per-body state; it lives on the player.
+
+### The hall as hub and lobby
+
+You launch into a place, not a menu. The lobby is a board by the door, readiness is a plinth you stand on, class
+is a locker with racks, and everyone is physically together before the run. The mechanism is **the lobby is a
+room**. Needs: a second map and session travel. Must not: assume a listen server; the room is on the same server
+the world is.
+
+### Steam lobbies and the friends-list join
+
+Every launch hosts a lobby of one; opening it to friends is a physical act; a friend's "join game" carries them
+in. Needs: a session layer in front of the server. Must not: put a session type inside gameplay code.
+
+### Content authoring tools
+
+Weighted pools, typed anchors, a tile template with red doorway volumes and a footprint validator, a project
+content catalogue feeding dropdowns, and one browser window over every content asset. The engine's data
+validation and asset manager do half of this natively. Needs: enough content to hunt through. Must not: arrive
+before the third tileset.
+
+### The design system
+
+A palette by role, one label component, one theme, meaning never on hue alone. **Adopted** in
+[UI.md](Spec/UI.md); the parchment-and-ink look itself is not.
+
+## From Project Malleable
+
+### Orders as tickets on a rail
+
+A customer hands over a parchment; it hangs on a rail from the desk to the workshop; taking it off is the claim;
+clipping it to a station shows what that station is working; handing it back with the item is the delivery. The
+spec on the ticket is explicit (family, required tags, minimum quality) and matched by one pure function that
+also explains why an item does not match. Five customer tiers as data, archetypes with patience and reactions.
+The mechanism is **demand as a physical object you can pick up, hand over and drop**. Needs: a shop, an
+economy, customers. Must not: be the only source of demand once players are the adventurers.
+
+### The economy
+
+Gold only. A payout split 20/40/40 between base, quality and speed against a tier price, clamped so the ceiling
+belongs to the order and profit is margin. A shared wallet with per-player attribution. A front shop with bid and
+ask prices, NPC valuation computed independently so player prices cannot mint money, and haggling as a turn-based
+exchange with a **truthful** likelihood meter. Needs: everything above it. Must not: introduce a lying surface;
+every gauge in this project tells the truth and a haggling meter that dramatised would poison the others.
+
+### Storage as a place
+
+No shop-wide inventory, no stack counters, no station pulling from a container across the room. Containers with
+slots, designated floor areas typed by what they hold, reservations per object so two players racing for the last
+ingot find out at claim time, nothing destroyed by a full container, and a satchel bought later that adds pocket
+slots (2, 3, 4, 6, 8, 10). The mechanism is **hauling is the game**, and the substance object model already
+assumes it. Needs: more things than hands can hold. Must not: add an abstract bank; the object model's cost is
+only affordable because storage caps the count.
+
+### Crafting domains as professions
+
+Five domains mapped one to one to five crafting classes (Forge Worker, Woodworker, Enchanter, Shopkeep,
+Quartermaster) with speed and quality bonuses that never lock anything. Three domains are **adopted** as the
+station gate in [Crafting.md](Spec/Crafting.md). The open question worth a real session: this project has combat
+kits; are crafting professions a second axis on the same player, a choice against a kit, or folded into kits?
+Needs: that decision. Must not: gate a station on a class; the rule is bonuses, never locks.
+
+### Stations you place, upgrade and pack
+
+Movable stations on a grid, per-station upgrades with a mesh per tier so level reads across the room, fittings as
+visible sub-upgrades in named sockets, and stations repackaged into a carryable crate rather than sold, so nothing
+is lost and no gold comes back. Needs: a place that is yours. Must not: put station state on the actor's
+Blueprint; it is a replicated record.
+
+### World events as a modifier service
+
+A standalone service any system asks for its own modifier (`GetModifier(PriceBias, tag)`), events as assets with
+scopes and channels, seeded per world, pushable from outside. The mechanism is **consumers ask, they never test
+for an event**. Needs: a second system that wants tuning from outside. Must not: be consulted from inside an
+activity tick.
+
+### Travel and the town
+
+The cart as the travel system: sit in it, pick a destination, cut to the scene. A town with a purchase surface
+and a small bounded warehouse, staged so that a local town cannot smuggle in shared population or a marketplace
+before the service that hosts them exists. Needs: a second place. Must not: make the warehouse a bank.
+
+### Persistence and portable characters
+
+Worlds keep the relationship, characters belong to the player and travel between worlds; ironman days with no
+rewinds and a mid-day autosave; records as idempotent snapshots with schema versions and recomputed derived
+fields; a provider interface with a local implementation forever. **Adopted as the identity and persistence
+seams** in [Networking.md](Spec/Networking.md); the day, the world record and the character record are not built.
+
+### The service posture
+
+Dedicated servers, a validation layer behind the simulation, three responsiveness tiers, ask-then-show, no
+rollback of visible world state, lag compensation only where timing is scored, and an incident doctrine (detect,
+contain with a modifier push, trace by object id, remediate surgically, restore last). **Adopted as posture** in
+[Networking.md](Spec/Networking.md) and [Telemetry.md](Spec/Telemetry.md). The layers themselves are not built and
+nothing in gameplay code would change when they are.
+
+### Adventure contracts, turned inside out
+
+Malleable sent NPC parties out with your gear to bring rare substances back. Here the players are the party.
+The loop that closes when the three feels exist: **craft a weapon, fight with it, bring back what only fighting
+finds, craft something better.** Rare substances as drops and finds with provenance already in the data model
+(`Provenance.Found`, `SourceObjectIds`). This is the most likely next step after fifteen and it is deliberately
+not written as one.
+
+### Discovery at scale, alloys, deciphering
+
+Generated glyphs discovered like skill unlocks (with the constraint that the composition path never changes and
+any seed is global), a kiln that alloys two raw types (with the constraint that nobody hard-codes one-to-one
+processing), and customer requests as rough descriptions to interpret rather than specs to read. Each is its own
+session. Must not: happen by accident in a step about something else.