The guide's seam table gets its third column: the example is a game on this server now, not a footnote #130

Three games ship here and the engine's guide still describes two.

GUIDE.md says "Two games ship here, and every place they differ is a place the engine chose to know nothing", and under the table: "The example is in no column: it brings a host, a table, a tick and its own tuning, and nothing else in this table at all." Since #80 landed that is no longer true — /example is served from the registry, src/example/main.ts brings a host, a bindings table and a tick, src/example/plan.ts is its frame as data, and it brings no atlas, no mesh, no sound and no agent. A reader deciding whether to build on this package reads that table first, and the most interesting column in it — the game that ships in 8.7 kB and uses none of the WebGL — is the one that is missing.

Waits for #116, which turns that table from four hardcoded string checks into something a test actually reads; this is the row work on top of it.

Done looks like

• [ ] The seam table has a third column, the example, filled honestly: its entry, its host and test helper, its bindings table, its tick, none where it brings nothing, and src/example/plan.ts as its frame as data.
• [ ] The paragraph above the table says three games, and the footnote about the example being in no column is gone.
• [ ] guide.test.ts's reading covers the new column: every path in it exists, every none is a word the test knows, and a fourth game added to src/games.ts with no column fails the test with a message saying which game is missing.
• [ ] The rows that are about WebGL say what the example does instead — it draws a plan through overlay on a 2D context — because that is the row a reader wants most.
• [ ] Nothing about the example's code changes; this is the guide and its test.

Files I expect to change

src/engine/GUIDE.md, src/engine/guide.test.ts.

Risks

• A table with three columns is wider than a terminal; keep the cells short and let the paragraphs carry the prose.
• Tying the column count to GAMES means the fourth game's pull must write its column. That is the intent — say it in the docstring so nobody is surprised.

Suggested: Vesper — the same hand that holds #116.