explain — decompress spec into prose

Inverse of the glyph skill (math-glyph encoder). Human-facing. Reads SPEC.md, expands one citation into plain English with cited context. Writes nothing.

LOAD

1. Read SPEC.md. If missing → "no spec, nothing to explain." Stop.
2. Parse $ARGUMENTS:

• §T.n / §V.n / §B.n / §I.<key> → that row
• §G / §C → that section in full
• --next or empty → lowest-numbered §T row with status .

1. Renumber-map probe — .claude/spec-renumber-map.json exists (written by reorganize skill per §V renumber permission) → on §V.<n> arg, walk old:V<n> → new:V<m> chain newest-first until not further mapping, then resolve substituted id against current SPEC.md. Read-only contract preserved per read-only-diagnostic invariant — map consulted, not mutated. not exist → arg resolves directly against current SPEC.md.
2. If citation absent → list valid ids in target section. Stop.

EXPAND

For the chosen citation:

1. Quote the raw math-glyph line(s) verbatim in a code block.
2. Restate in plain English. No math-glyphs, no fragments — full sentences.
3. Pull in cited siblings:

• §T row → expand every §V and §I it cites.
• §V row → list §T tasks that cite it and §B bugs that reference it.
• §B row → expand the §V it broke and the fixing §T.
• §I row → name §V invariants that constrain it.
• §G / §C → no cross-cites; just prose.

1. Close with one line: what the reader should now understand.

OUTPUT SHAPE

## §T.<n> — add auth middleware

> T<n>|.|add auth mw|V<n>,I.api

In plain English: this task adds an authentication middleware that runs before
every request reaches its handler.

Cited invariants:
- §V.<n> — every request must pass an auth check before the handler runs.

Cited interfaces:
- §I.api — POST /x returns 200 with {id:string}; the middleware must not
  change this shape.

Status: not started (`.`).

Bottom line: implement a middleware that enforces §V.<n> without altering §I.api.

## Hint

§T.<n> is pending — typical next step is item 1 to start work, or item 2 if you want to read the cited invariant first.

## Next

1. /sdd:build §T.<n> — start implementation
2. /sdd:explain §V.<n> — read the cited invariant in prose

OUTPUT — "Next" block

Heading ## Next; 1–5 atomic items (one sentence each, no Reply prefix); positional dispatch (run <int> or run /<plugin>:<cmd> [args]). Optional ## Hint (≤ 3 lines) precedes when item selection needs hidden state (closed-vs-pending row implications, citation-form edge cases). explain is read-only so items are slash-cmd follow-ups: /sdd:build §T.n only for . rows; closed x rows → /sdd:explain --next or /sdd:check.

Example for a closed §T row (terminal state):

## §T.<n> — add auth middleware

> T<n>|x|add auth mw|V<n>,I.api

In plain English: this task added an authentication middleware...

Status: complete (`x`).

Bottom line: §V.<n> is enforced by the middleware shipped under §T.<n>.

## Hint

Closed rows are historical. `run 1` skips to live work; `run 2` audits whether the closed task drifted out of code.

## Next

1. /sdd:explain --next — read the next pending §T row
2. /sdd:check — audit whether the closed task still holds

The "Bottom line" sentence stays — it summarizes the citation, it does not direct action. Action lives only in Next; pre-action context lives in optional Hint.

NON-GOALS

• Zero writes. No SPEC.md edits. No code edits.
• No code reads. Spec-only. (Use /sdd:check if you want spec-vs-code.)
• No math-glyphs in output. Prose is the whole point.
• No multi-citation expansion in one call. One id per invocation; loop if needed.