Contract 6.25.0

The elixir family, after the Elixir Gym's first run on it (feedback #118-#123), and every tool with an outputSchema.

• elixir_timeline's item cap now cuts cleanly (#120). When a cap leaves items out, the page stops before the first of them, next_cursor continues exactly there, has_more is true, the read pointer moves only to the cut, and timeline_more counts the items still to read after the kind and section filters. Before, the newest items were dropped while the cursor pointed past them, so a reader on the pointer lost them for good.
• Every timeline item carries observed_at, when the record saw it, which is what selects it into a window, beside at, when it happened. A note says so when items dated before from are served (#118).
• A quiet_crossed moment's facts are as of the crossing: days_quiet is the rung. days_since_poll is null, not negative, when the only poll known came after the window's end (#119).
• The moment ledger's history is stated: profile-derived moments begin 2026-09-14T04:27Z, and steps from before the step rule carry step: null. A moment written twice (#48) is served once (#121).
• result_too_large gives the actual size, stops telling a compact call to use compact, and names kinds and sections where a tool takes them (#122). elixir_my_identities and elixir_docs page reads carry notes, and the page reads a docs pointer (#123).
• All 55 tools publish an outputSchema; 6.14.0 said so, and nine had none (#115). A test now holds it.

Additive: observed_at, step null, has_more/next_cursor now honest on a capped window.