feat: scienting-math/1 sources and derived/math.jsonl; lode references; stress fixes

Math content may say its source is in scienting-math/1's canonical TeX (form,
in no hash); derived/math.jsonl holds papermath's tree, symbols and issues,
and the validator now checks derived files. A symbol annotation names its
symbol by key; lode claim references use lode's tag and pin syntax. The zip
reader refuses entries zipfile cannot read, and checkpoint lines end in LF only.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_017R7sgDNvUGWY2zFPCq2JH6

schemas/README.md

@@ -1,6 +1,6 @@
 # Schemas
 
-This folder holds the JSON (JavaScript Object Notation) Schemas (draft 2020-12) for every file and record that the paperspec formats (paperspec is the specification this repository holds) define: 42 schema files.
+This folder holds the JSON (JavaScript Object Notation) Schemas (draft 2020-12) for every file and record that the paperspec formats (paperspec is the specification this repository holds) define: 43 schema files.
 A JSON Schema is a file, itself written in JSON, that states what a valid JSON file looks like.
 Newcomers can read it as a form: it lists the fields a record must have and what kind of value each field takes.
 Implementers will find the loading recipe and the traps under "Validating" and "Writing schemas".
@@ -20,7 +20,7 @@ The number after each name is the chapter of `spec/` that defines the file.
 | Topic | Schemas (chapter) |
 | --- | --- |
 | Shared definitions | `common.schema.json` (1): hashes, IDs, keys, addresses, times, decimals, boxes, licenses, signatures, evidence, quotes. |
-| A package | `manifest.schema.json` (12), `document.schema.json` (2, 12), `node.schema.json` (3), `runs.schema.json` (3), `witnesses.schema.json` (2), `provenance.schema.json` (12), `page.schema.json` (7), `location.schema.json` (7), `reference.schema.json` (10), `id-entry.schema.json` (4), `correction.schema.json` (11), `receipt.schema.json` (8), `revocation.schema.json` (8), `roster.schema.json` (8), `suspect.schema.json` (5), `mathml.schema.json` (12) |
+| A package | `manifest.schema.json` (12), `document.schema.json` (2, 12), `node.schema.json` (3), `runs.schema.json` (3), `witnesses.schema.json` (2), `provenance.schema.json` (12), `page.schema.json` (7), `location.schema.json` (7), `reference.schema.json` (10), `id-entry.schema.json` (4), `correction.schema.json` (11), `receipt.schema.json` (8), `revocation.schema.json` (8), `roster.schema.json` (8), `suspect.schema.json` (5), `mathml.schema.json` (12), `math.schema.json` (9, 12) |
 | Pointing into documents | `anchor.schema.json` (6) |
 | Rights | `rights.schema.json` (14), `policy.schema.json` (14), `stages.schema.json` (14), `backend.schema.json` (14), `profile.schema.json` (14), `stamps.schema.json` (7) |
 | Review | `qa-report.schema.json` (8), `spot-check.schema.json` (8), `checklist.schema.json` (8), `proof.schema.json` (8, 11) |
@@ -37,7 +37,8 @@ The Data schemas for datasets, digitizations and views, the Teams and drafts sch
 The rest belong to `candidate` formats or to no format of their own.
 
 The bundle has no JSON Schema: its registry entry points to `sql/bundle-sqlite.sql`.
-Of the 42 schemas, 11 have no format of their own because each describes a line or part of a larger file: `common`, `node`, `runs`, `witnesses`, `provenance`, `location`, `reference`, `id-entry`, `mathml`, `annotation` and `value-anchor`.
+Of the 43 schemas, 12 have no format of their own because each describes a line or part of a larger file: `common`, `node`, `runs`, `witnesses`, `provenance`, `location`, `reference`, `id-entry`, `mathml`, `math`, `annotation` and `value-anchor`.
+A line of `derived/math.jsonl` carries `form`, the math form `scienting-math/1` it reads the formula in; that names a spelling of TeX, which papermath implements ([spec/09 §9.4](../spec/09-figures-tables-equations.md#94-the-math-form)), not a file format, so the registry does not list it.
 Of the schemas that do have one, 27 require a `format` property; `spot-check.schema.json` describes the input a VRF proof is made over rather than a file.
 The others (`page`, `draft-ids`, `view` and `log-entry`) describe a line of a file, a Vega-Lite specification (a JSON description of a chart) or an item of a tree, and the record itself does not need to carry the identifier.