Cut non-essential prose from docs and comments, and require the same of every future change

README loses the competitor comparison, the personas and the repeated philosophy; the
five near-identical E2E command blocks become a table plus one command, and the file
map a clause per entry. AGENTS.md keeps every decision but drops the narrative around
them. todo.md's completed items collapse to their task line — git holds the rest.

Comments lose restatement, README duplication and history ("used to", "originally",
dated notes). AGENTS.md gains a Prose discipline section making this a standing pass on
every change rather than a one-off cleanup.

src/compose.test.ts now expects 6 documented E2E run commands, not 10, since the README
states the command once instead of per suite.

e2e-tests/full-flow.spec.ts

@@ -50,8 +50,8 @@ test.describe.serial("authenticated admin journey", () => {
   });
   test.afterAll(async () => { await page.context().close(); });
 
-  // The list screens rebuild their query from the list state (sort/page/filter), so they are where
-  // a chosen language used to get dropped — the core building blocks carry it now.
+  // The list screens rebuild their query from the list state (sort/page/filter), so they are where a
+  // chosen language is most easily dropped; the core building blocks carry it through.
   test("a sorted, paged admin list keeps the visitor's language", async () => {
     await page.goto("/admin/users?locale=sv-SE");
     await expect(page.locator("html")).toHaveAttribute("lang", "sv-SE");