feat: template plugin system for board data models (NEBULA-79)

[exisz]

Implements NEBULA-79 — the plugin-based template system that backs dna://convention/project-data-model-declaration.

What

Boards now declare their data model via a pinned 🧬 DATA MODEL: <id> card. Templates are pluggable — built-in, user-local (~/.agentbase/templates/), or npm packages prefixed agentbase-template-*. Core stays template-agnostic; the loader + validator + model card parser do the rest.

New CLI

agentbase template ls                         # list installed templates
agentbase template info <ID|PATH>             # template details + schema check
agentbase template scaffold <ID> [-o FILE]    # starter YAML for new template

agentbase model show     [-b BOARD]           # explain board's data model
agentbase model validate [-b BOARD]           # check board against template rules
agentbase model declare  [-b BOARD] -t <ID>   # add the model card to a board

Built-in templates

• status-pipeline — formalises the legacy kanban default
• correspondence-versioned — mirrors the hand-built rffi board (round-based collection)

Backward compatibility

Boards without a 🧬 DATA MODEL card are treated as status-pipeline@0 (assumed default). No config migration needed.

Verified

$ agentbase model show -b rffi
Board:    69e8c9a7513c41482cfc2151
Template: correspondence-versioned (v1) — source: builtin
... full axes + statuses + required-lists rendered ...

$ agentbase model validate -b rffi
✅ PASS — no findings.

$ npm test
✔ 10/10 tests pass

A fresh sub-agent given only agentbase model show -b <board> can now answer "what does each list mean?" — the success criterion in the design doc.

Companion work (separate from this PR)

• Design doc: ~/.openclaw/workspaces/nebula/agentbase-templates-design.md
• Convention: ~/.openclaw/.dna/conventions/board-template-plugins.md
• Follow-ups (future PRs): publish agentbase-template-status-pipeline and agentbase-template-correspondence-versioned as standalone npm packages to demonstrate the discovery contract; implement render-hook view bus (matrix view for correspondence-versioned); hook event dispatch.

Schema

See design doc §5 for the full template YAML schema. Minimum viable template needs only id, version, name, axes, status-schema.values — everything else is opt-in.

Tests

• src/templates/templates.test.ts — 10 tests covering loader discovery, schema validation (built-in templates pass; bad inputs caught), board-against-template validation (rffi fixture passes; missing model card and missing required lists fail).

NEBULA-79

[exisz]

Squash-merged directly to main. Empire owners (nebula) follow dna://protocol/basic — direct push to main, no PR. CONTRIBUTING.md PR flow applies to external contributors only.