[02.1 follow-up] Fix SpellPower review issues from PR #78

[alseif0x]

Follow-up for the unresolved chatgpt-codex-connector review threads left on merged PR #78 ([02.1][M0.1] Load SpellPower costs and deduct cast power). Keep this as a focused SpellPower correctness PR, separate from #73 CombatRatings.

Context

PR #78 landed SpellPower cost loading and represented power deduction, but these review threads are still unresolved and not outdated:

• [02.1][M0.1] Load SpellPower costs and deduct cast power #78 (comment) — delay power deduction until cast validations pass.
• [02.1][M0.1] Load SpellPower costs and deduct cast power #78 (comment) — queued casts must still check/deduct power when they execute.
• [02.1][M0.1] Load SpellPower costs and deduct cast power #78 (comment) — clear stale mana power index for non-mana classes.
• [02.1][M0.1] Load SpellPower costs and deduct cast power #78 (comment) — send saved current power on login, not max power.
• [02.1][M0.1] Load SpellPower costs and deduct cast power #78 (comment) — persist deducted power before logout/disconnect.

C++ anchors

• Spell::CheckCast / Spell::CheckPower / Spell::TakePower: /home/server/woltk-trinity-legacy/src/server/game/Spells/Spell.cpp
• Player::GetPowerIndex and DB2Manager::GetPowerIndexByClass: /home/server/woltk-trinity-legacy/src/server/game/Entities/Unit/StatSystem.cpp, /home/server/woltk-trinity-legacy/src/server/game/DataStores/DB2Stores.cpp
• Player::SaveToDB / CHAR_UPD_CHARACTER power fields (power1..power10): /home/server/woltk-trinity-legacy/src/server/game/Entities/Player/Player.cpp, characters prepared statements

Do

• Split represented power handling into C++-like check vs take phases:
  • CheckPower should fail before cast start/execution when current power is insufficient.
  • TakePower should deduct only after represented cast-failure gates pass, before SMSG_SPELL_GO, matching C++.
  • Queued casts must run the same check/take path at execution time.
• Fix canonical player power index setup so non-mana primary power classes do not keep stale POWER_MANA -> slot 0 mapping.
• Login self UpdateObject should represent the saved current slot-0 power, not the max value, when DB current power is lower.
• Logout/disconnect persistence should write represented current powers (power1..power10) back to characters where Rust has authoritative canonical/session power state.

Tests

Add focused positive/negative tests for:

• no power => CastFailed(NoPower) and no deduction.
• represented later cast failure => no deduction.
• queued cast => no free cast; checks and deducts when executed.
• non-mana class with mana-cost spell does not spend rage/energy/runic power as mana.
• login current power below max is sent/represented correctly.
• logout/disconnect save snapshots include updated power fields.

Validation

Use the usual issue workflow:

PROTOC=/home/cdmonio/.local/protoc/bin/protoc cargo test -p wow-world <focused tests> --lib
PROTOC=/home/cdmonio/.local/protoc/bin/protoc cargo check -p world-server
cargo fmt --all -- --check
git diff --check

Done means tests + live validation of a spell power spend/relogin flow against the running server, with C++ behavior rechecked before implementation.

[alseif0x]

Live validation update: after the latest fix, current mana/power now remains across relog. Follow-ups split out of #79 scope: #81 for rested XP/offline rest-state parity, and #82 for current health save/load parity. #79 should stay focused on SpellPower/current-power review fixes from PR #78.