feat(plugin): publish Panorama Viewer v0.2.0

[superche]

What changed

• add Panorama Viewer v0.2.0 as a formal convax.plugin/4 workspace package
• publish Chinese package metadata and the redesigned labeled controls
• include current-viewport capture support
• declare canvas.image.write and canvas.image.create
• extend manifest schemas and repository capability validation
• bump Registry sequence to 28
• add package-specific and Registry tests

Why

The optimized Panorama Viewer must be independently installable from the Convax Registry, while relying only on documented host capabilities supplied by the matching Convax host change.

Impact

Users can install the optimized Panorama Viewer from the Plugin catalog and use its Chinese title, explicit toolbar controls, and screenshot-to-Canvas workflow.

Validation

• bun install --frozen-lockfile --ignore-scripts
• trusted package workspace builds and typechecks
• bun run validate
• bun run build:companions
• bun test — 233 passed
• bun run pack
• bun run build:index

Host dependency

Requires microvoid/convax#41, which adds the canvas.image.write / canvas.image.create host path.