show --json --deltas-only reports an invented MODIFIED for a bullet-form REMOVED, while archive deletes the requirement #1855

Description

openspec show <change> --json --deltas-only is the command OpenSpec's own
error text recommends for inspecting parsed deltas
(src/core/validation/constants.ts:61: "Tip: run openspec change show <change-id> --json --deltas-only to inspect parsed deltas"). It reads deltas
through ChangeParser, which is a second delta reader, separate from
parseDeltaSpec, the one archive applies. The two disagree.

For a REMOVED written in the bullet form, the same change is described in two
contradictory ways:

• show reports one MODIFIED delta, invented from the proposal's "What
  Changes" prose.
• archive removes the requirement.

Reproduction

Main spec openspec/specs/billing/spec.md has Invoice Generation and
Late Fees (written by archiving a first change). The proposal's What Changes
is - **billing**: updates billing requirements. Delta:

## REMOVED Requirements
- `### Requirement: Late Fees`

openspec show edit --json --deltas-only
# deltaCount: 1, deltas: [{ operation: "MODIFIED", description: "updates billing requirements" }]

openspec archive edit --yes
# Totals: + 0, ~ 0, - 1, → 0   (Late Fees is deleted from the main spec)

Control: the same removal written as a header (### Requirement: Late Fees +
**Reason**: ...) is shown as REMOVED.

Expected

show reports what archive will apply: one REMOVED delta for Late Fees. It
should never report proposal prose as a structured operation.

Actual

show reports a MODIFIED that does not exist, and hides the deletion.

Three shapes are affected, all of them accepted by archive:

Root cause

src/core/parsers/change-parser.ts:

• :137 reads REMOVED only from ### Requirement: header children. The bullet
  form that parseRemovedNames (requirement-blocks.ts:333) accepts is
  invisible to it.
• :106, :122, :137, :152 use findSection, which returns the first
  match only. parseDeltaSpec reads every copy (fix(parser): apply every delta section header #1802).
• :175-176 (parseRenames) accepts only - or no bullet. parseDeltaSpec
  accepts every CommonMark marker (fix(parser): accept all CommonMark list markers in deltas #1800).
• :36 and :43: when the spec files yield no structured delta, the parser
  falls back to the proposal's "What Changes" bullets, and reports them as
  operations.

The parser's own comment at :87 states the goal: "keep the two readers in
agreement".

Impact

The recommended inspection command misreports a deletion as a modification.
A reviewer or an AI agent checking a delta before archiving is told that a
requirement will be edited when it will be deleted. The same reader also feeds
openspec change list delta counts.

Environment

• OpenSpec 1.13.0 (reproduced on the published npm package and on a build of
  main @ 9d4e597)
• Node v20.19.0 and v22, Linux
• Reproduced in a project created entirely by openspec init +
  openspec new change, with the baseline main spec produced by archiving a
  first change