[Bug]: check-prerequisites.sh never validates spec.md although it resolves and exports FEATURE_SPEC #4364

Bug Description

scripts/bash/check-prerequisites.sh validates FEATURE_DIR, plan.md, and — under --require-tasks — tasks.md, each with an actionable error naming the command to run:

echo "ERROR: plan.md not found in $FEATURE_DIR" >&2
echo "Run /speckit-plan first to create the implementation plan." >&2

FEATURE_SPEC is resolved, exported in the JSON payload and printed in text mode (5 occurrences in the file), but its existence is never checked.

Both /speckit-analyze and /speckit-converge invoke the script as check-prerequisites.sh --json --require-tasks --include-tasks and then read the spec directly — SPEC = FEATURE_DIR/spec.md, followed by a "From spec.md" extraction section. When spec.md is missing, the prerequisite check passes and the failure surfaces later, without the "Run /speckit-specify first" guidance the script provides for every other artifact.

For accuracy: /speckit-implement does not read spec.md, so this affects analyze and converge.

Steps to Reproduce

1. Create a feature, then generate plan.md and tasks.md.
2. Delete or rename specs/<feature>/spec.md.
3. Run .specify/scripts/bash/check-prerequisites.sh --json --require-tasks --include-tasks.

Expected Behavior

The same treatment as plan.md and tasks.md: an explicit error pointing at /speckit-specify. If spec.md is legitimately optional for some callers, gating it behind a --require-spec flag would keep the check opt-in while still making it available to analyze and converge.

Actual Behavior

Exit 0, with FEATURE_SPEC reported as a path that does not exist. analyze and converge then fail further downstream with a less actionable error, which is precisely what this script exists to prevent.

Specify CLI Version

1.0.1 — and still present on main at the time of writing.

AI Agent

Claude (not agent-specific: the script is shared by all integrations).

Operating System

macOS — not OS-specific.