feat(lua): asobi_lua_match_shared bridge for encode-once broadcast

[Taure]

Summary

Companion to asobi#117.

• New asobi_lua_match_shared bridge module that delegates init/join/leave/handle_input/tick/vote_* to asobi_lua_match and exports get_state/1 calling Lua's one-arg get_state(state)
• asobi_lua_config reads a new state_strategy global from match.lua and adds state_strategy => shared to the mode config so asobi's resolver picks this bridge

Lua scripts opt in by adding to match.lua:

```lua
state_strategy = "shared"

function get_state(state)
return { ... } -- one shared payload, no per-player view
end
```

Why

asobi#117 enables encode-once-per-tick broadcast for shared-state games via an optional get_state/1 callback. Static Erlang exports + Lua's lack of arity make a single dual-mode bridge awkward, so the cleanest expression is two bridge modules selected by a script-level flag. Existing {lua, Script} configs continue resolving to asobi_lua_match (per-player) — backward compatible.

Test plan

• rebar3 fmt --check clean
• rebar3 xref clean
• rebar3 dialyzer clean
• ~/bin/elp eqwalize-all zero new errors (43 pre-existing)
• ~/bin/elp lint zero new warnings on changed lines
• rebar3 eunit 201/201 green
  • new asobi_lua_match_shared_tests (init/lifecycle/get_state/1)
  • new config test asserts state_strategy = "shared" end-to-end resolves to asobi_lua_match_shared
• Pin bump asobi after asobi#117 merges
• Re-bench via asobi-bench to confirm p99 improvement