backdraft 0.14.0

A week on getting from where a command points to the passage it means: chunk reads, search excerpts that show the match, and reports that say what to do next.

• backdraft read <slug> p1.c9 and p1.c9-c14 read the chunks a table of contents lists, by the locator it prints. What a chunk read prints is minted exactly as a page read's is; a range clips to the chunks that exist, runs past the budget with the same continuation line, and a backwards or empty range exits 1 naming the page's chunk span. A sheet refuses the form and says how it is read and cited.
• search excerpts now open on the words that matched. A hit whose match the first 160 characters already show prints exactly what it did; otherwise the excerpt moves to the densest run of matches, at a word, elided at whichever end it was cut. Display only: no token, receipt or record moves.
• bind and verify reports close with one next: line per kind of failure they printed, naming the exact command to run with the document and session filled in — show for not_shown, search for unresolved, locate for drifted, a rebuild for an edited artifact. A clean report is byte-identical to before; --json is unchanged by it.
• verify now re-checks not_shown against the ledger session the record names, when that session is in the registry it checks against — the one check that says the author read what they cited. A ledger: line says when it could not be asked (the session is not in this registry, or the bind had none). verify --json gains sources.ledger.
• A spreadsheet or CSV is no longer marked little text for being short: a sheet is marked only when none of its cells holds a value, so a three-row rate table is cited like any other source.
• A registry locked by another writer, or otherwise unopenable, is no longer called damaged with advice to restore it; the message says nothing changed and to run again when the other writer finishes.

1645 tests.