Add Deal Redux assistant workflow

[czocher2-boop]

Adds assistant-workflows/deal-redux/SKILL.md.

What it does

Turns a counterparty's tracked-changes redline into the small number of negotiating positions it actually contains, and returns that instead of a counter-redline. A counterparty sends eighty-four edits; they contain six positions; send back the six.

Design decisions worth flagging

• The response column is left blank. The workflow reports what the redline does to the operative text. The lawyer decides what to do about it. It never fills that column, suggests a fill, or characterises a position as reasonable, aggressive, or market.
• Classify by effect, never by the counterparty's comment. A comment is the other side's characterisation of its own edit.
• Conservation check. Every tracked change must land in exactly one position or one of two counted buckets, and the arithmetic is printed on the face of the output. If the unaccounted number is not zero, the reduction is not finished. A compression whose value is that you can stop reading the document fails the first time something material was left out of it.
• The ratio is reported, not argued. 84 → 6 with no editorialising. A measurement can be sent to a counterparty where an accusation cannot.
• It does not detect or allege AI use. A redline that collapses from eighty-four edits to six positions was overproduced whoever made it.

Compliance

• Folder, name, and slug of metadata.mike-display-name all agree (deal-redux / "Deal Redux").
• mike-availability: "add-on", mike-type: "assistant", all metadata values are strings.
• Harness-neutral: no CLI commands, no named tools, and no file-format or object-model specifics — the extraction step describes what to pull rather than how.
• Original work, submitted under the repository's MIT license.
• python3 workflow-schema/validate-workflows.py passes: 143 workflows, 16 column files, 5 packs.