Expression kitchen sink

Every worked example in the db's base_expression_example, live — each one a real <enumeratio-expression> wrapped in <enumeratio-assert>. So this page is itself a full-stack unit-test run: the same battery the CLI's expression-examples.test.ts checks in Node, here evaluated in a real browser through the actual web component and pglite. The scoreboard at the top should read all passing.

Filter by tag (identity, edge-case, singleton, precedence, norm). New examples added to the seed show up here automatically — add more, and the coverage grows.

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Want just the singletons — bare element literals that parse and render back? Filter to singleton above, or see the parsing a singleton element section.