[finding] hono UI auto-discovery: the slug-from-name fallback and the staticPath guard are unreachable through kernel.use() once PluginSchema requires both keys (#16334)

[huangyiirene]

Observation from #16334 (spec half of #16049), filed unassigned. Sub-issue of #15638 because it is the same block and the same class — an arm of the auto-discovery block in packages/plugins/plugin-hono-server/src/hono-plugin.ts (around line 508) that no object can reach any more.

What is dead, and since when

• const slug = plugin.slug || plugin.name.split('/').pop(); — the || fallback. With spec: PluginSchema makes staticPath / slug really required for type: "ui" (superRefine), and core's Plugin interface derives from PluginDefinition (spec half of #16049) #16334, PluginSchema refuses a type: 'ui' plugin without slug, and kernel.use() runs the schema ([finding] PluginSchema has zero runtime callers — the boot path validates name, init and semver only, so the declared plugin contract is never enforced #16049, landed as feat(core): enforce PluginSchema at kernel.use() (#16049) #16363), so a ui object with no slug never reaches kernel.plugins, the only population the block iterates.
• if ((plugin.type === 'ui' || plugin.type === 'ui-plugin') && plugin.staticPath) — the && plugin.staticPath conjunct, for the same reason (staticPath is required for ui too). The ui-plugin disjunct is [finding] plugin-hono-server still accepts the legacy ui-plugin type that PluginSchema refuses — an unreachable arm under ADR-0049 #15638's own subject and was already unreachable after feat(core): enforce PluginSchema at kernel.use() (#16049) #16363.

Evidence. The two pins that exercised those branches through the real kernel — "derives the slug from the last path segment of the plugin name when none is declared" and "a ui type with no staticPath mounts nothing" in src/ui-plugin-auto-discovery.pin.test.ts — had to be inverted into refusal pins on the #16334 PR (#16598): with the schema tightened, kernel.use() throws PLUGIN_CONTRACT_VIOLATION … at 'slug' / at 'staticPath' before start() ever runs. The it.todo for case C in that file still narrates a boot path that "never calls PluginSchema", which stopped being true at #16363.

Left out of #16334 by scope. Retiring the two arms is a plugin-hono-server change with its own verification surface, and #15638 already owns the third arm of the same guard. Suggested shape, for whoever lands it: read plugin.slug and plugin.staticPath as the contract now guarantees them, drop the fallback and the guard, and rewrite the case-C todo against the post-#16363 boot path. The same block also reads an isDefault alias beside default (plugin.default || plugin.isDefault); isDefault is not a PluginSchema key and is worth a look in the same pass.