Combat disciplines: build the action framework and Sweeping Cleave slice

[zoeyrose]

Important

This issue is implemented in the fresh MIT-licensed Go server under the replacement program. Its gameplay and content-design decisions remain authoritative. C, CPython, classic packet, file-path, and enum details in the preserved specification are historical evidence only; do not copy, translate, or structurally port GPL implementation code.

Replacement implementation contract

Use this as the first action-system vertical slice: explicit Go action context, bounded deterministic shape queries, compiled profiles/nodes, persistence, and generated Rust presentation contracts. Sweeping Cleave proves the general framework.

The server remains authoritative, consumes versioned compiled content, and exposes bounded generated Game Protocol 1 messages. Pure rules may use a specifically approved typed CEL environment. Starlark is not part of this issue unless the separate residual-scripting decision explicitly approves it.

Required verification

• Preserve every observable rule, balance decision, disclosure boundary, and anti-exploit invariant from the specification below.
• Add deterministic Go unit/property tests and wrapper-managed scenario coverage at the appropriate integration boundary.
• Add bounded malformed-input and persistence-failure cases where this feature accepts content, network, or stored data.
• Add Go/Rust protocol conformance fixtures for every new cross-process field; the client must not reconstruct authoritative rules from prose.
• Demonstrate that implementation and tests contain no copied GPL source/test material and execute no runtime Python.

Preserved product/design specification and historical implementation notes

Parent and roadmap

• Parent tracker: Add data-driven combat disciplines, weapon techniques, and mastery trees #27
• Roadmap: Roadmap: replace classic Atrinik with a fresh MIT Go and Rust stack atrinik#168
• Roadmap milestone: M3
• Prerequisites: Define stable combat-discipline and spell-tradition identities #18, Replace post-action cooldowns with server-authoritative wind-ups and timed animations #25, Proposal: centralize deterministic server clocks, deadlines, and test time atrinik#155, Modernization: adopt bounded packet cursors, protocol definitions, and fuzzing atrinik#190

Outcome

Deliver the reusable combat-action/shape/profile/tree foundation through one server-authoritative Sweeping Cleave vertical slice.

Scope

• Add explicit combat action/source context for melee and delayed projectiles with snapshotted discipline, weapon/profile, technique, scalars, and proc policy.
• Add bounded deterministic arc/ring/line/fan/radius target collectors respecting walls, tiled edges, depth, friendship/PvP, multipart identity, and target caps.
• Add validated combat-profile and technique/mastery registries with stable IDs, graph checks, bounded tuning fields, and persisted discipline-local selections.
• Implement Sweeping Cleave plus 2–3 axe/cleaver Masteries and the minimal bounded protocol, client tree, quickslot, cooldown, rejection, and respec path.

Superseded path / cleanup target

Remove temporary mutation of chosen_skill/weapon state and any cleave-only damage loop. Do not infer sweep from ATNR_CLEAVE or retain a parallel action timer.

Acceptance criteria

• Primary and secondary targets receive deterministic independent normal attack resolution without recursive techniques or duplicate multipart hits.
• Profiles control eligibility; rapier, dagger, and spear negative controls cannot use Sweeping Cleave.
• Selections, points, prerequisites, refunds, cooldowns, reconnect state, and malformed requests are server-authoritative and tested.
• Delayed kills credit the skill/action source captured when the action began.

Validation baseline

Before: attack calls rely on ambient actor state and there is no reusable bounded multi-target or technique contract.

After: one action framework supports a complete player-visible technique slice and later combat/monster reuse.

Run server action/shape/profile/tree tests, client/protocol tests, PvP/friendship/multipart fixtures, sanitizer builds, and GCC/Clang/MinGW builds.

This issue is a bounded child of #27. The parent remains open until every sibling child is complete.