[Draft] Add Discord event post templating and publish/export workflow

[BASIC-BIT]

Problem

Event text should be bidirectional. VRDex should be able to ingest Discord posts into structured events, but it should also help operators turn structured VRDex events back into Discord-ready posts or bot-published messages.

Scope

• Define a template model for event posts and slot lineups.
• Support generated Discord timestamp tokens from canonical event/slot times.
• Support previewing Discord-ready output before publishing.
• Allow communities to define or refine templates with an assistant-backed workflow.
• Support export-to-clipboard first, with direct Discord posting as a later gated path.
• Preserve generated short links and canonical URLs where available.

Non-Goals

• Replacing Discord event management entirely.
• Posting to Discord without explicit operator approval.
• Broad arbitrary-template code execution.
• Paid newsletter or cross-platform campaign tooling.

Acceptance Criteria

• A structured VRDex event can produce a Discord-ready text preview.
• Templates can include event fields, slot fields, canonical links, and Discord timestamps.
• Operator approval is required before any external posting path.
• Template behavior is documented well enough to avoid hidden prompt-only formatting rules.

Related Foundations

• [Draft] Add core event model and CRUD flows #34
• [Draft] Add event media links, poster image, and optional world linkage basics #36
• [Draft] Document public API posture, rate limiting, and open platform rules #39
• [Draft] Add durable generated short links for profiles, worlds, and events #92
• Define agent-consumable VRDex integration kit and MCP roadmap #73

Related Follow-On Issues

• [Draft] Define tool-first website scheduling assistant #118
• [Draft] Add DJ slot modeling and Discord timestamp helpers #119
• [Draft] Add AI-assisted event ingestion from Discord text and posters #120

Docs To Update

• docs/planning/product-spec.md
• docs/planning/architecture.md
• Future developer docs for Discord integration.

Suggested Labels

• phase:v1.5
• area:events
• area:discord

[BASIC-BIT]

Planning decisions from follow-up discussion:

• Ship this together with [Draft] Add AI-assisted event ingestion from Discord text and posters #120 after [Draft] Add DJ slot modeling and Discord timestamp helpers #119 lands.
• Start with a Discord-ready textbox / copy-to-clipboard export flow.
• Scope direct Discord bot posting as follow-up work rather than first-slice behavior.
• Treat templates as deterministic rendering rules over canonical event data, not arbitrary executable code and not prompt-only formatting behavior.
• Revisit community-authored or agent-authored templates after the first default export path is clear.

Likely follow-up issues after the first copy/export slice:

• Direct Discord bot posting with approval, audit logging, channel permissions, rate limits, and failure handling.
• Community-managed saved Discord post templates.
• Agent-assisted template authoring/editing with deterministic validation.
• Discord embed/unfurl polish for event pages and slot lineups.