docs: refresh engineering runbooks

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Summary

• Updated engineering, configuration, architecture, setup, database, feature, command, and contributing docs.
• Corrected source-verified behavior for event loading, release automation, command deployment, Prisma setup, MongoDB URI selection, ticket/JTC constraints, rank command usage, and test inventory.

Codepaths Covered

• src/handlers/events.js
• .github/workflows/release.yml
• src/events/ready/registerCommands.js
• src/events/ready/registerContextMenus.js
• src/handlers/deploy.js
• src/example.config.js
• src/commands/slash/General/rank.js
• src/components/selects/ticketSSM.js
• src/components/modals/ticket-modal.js
• src/components/buttons/ticket-close.js
• src/events/Guild/jointocreate.js
• tests/*.test.js

Knowledge Gaps Addressed

• Removed stale event-loader caveat now covered by object-module registration tests.
• Clarified release creation is gated by missing v<package.version> tag, not a latest-commit version diff.
• Documented DEV_GUILD_ID command registration paths versus config.handler.guildId developer-command deployment.
• Called out setup/runtime pitfalls: explicit npx prisma generate, external nodemon, MongoDB PRODUCTION=false truthiness, ticket panel/parent behavior, JTC setup limitations, and required /rank info <user>.

Validation

• git diff --check HEAD~1..HEAD
• npm test (37 passing)