Gsd:add Backlog

<objective>

Add a backlog item to the roadmap using 999.x numbering. Backlog items are

unsequenced ideas that aren't ready for active planning — they live outside

the normal phase sequence and accumulate context over time.

</objective>

<process>

• Read ROADMAP.md to find existing backlog entries:

   cat .planning/ROADMAP.md

• Find next backlog number:

   NEXT=$(gsd-sdk query phase.next-decimal 999 --raw)

If no 999.x phases exist, start at 999.1.

• Add to ROADMAP.md under a ## Backlog section. If the section doesn't exist, create it at the end.

Write the ROADMAP entry BEFORE creating the directory — this ensures directory existence is always

a reliable indicator that the phase is already registered, which prevents false duplicate detection

in any hook that checks for existing 999.x directories (#2280):

   ## Backlog

   ### Phase {NEXT}: {description} (BACKLOG)

   **Goal:** [Captured for future planning]
   **Requirements:** TBD
   **Plans:** 0 plans

   Plans:
   - [ ] TBD (promote with /gsd:review-backlog when ready)

• Create the phase directory:

   SLUG=$(gsd-sdk query generate-slug "$ARGUMENTS" --raw)
   mkdir -p ".planning/phases/${NEXT}-${SLUG}"
   touch ".planning/phases/${NEXT}-${SLUG}/.gitkeep"

• Commit:

   gsd-sdk query commit "docs: add backlog item ${NEXT} — ${ARGUMENTS}" .planning/ROADMAP.md ".planning/phases/${NEXT}-${SLUG}/.gitkeep"

• Report:

   ## 📋 Backlog Item Added

   Phase {NEXT}: {description}
   Directory: .planning/phases/{NEXT}-{slug}/

   This item lives in the backlog parking lot.
   Use /gsd:discuss-phase {NEXT} to explore it further.
   Use /gsd:review-backlog to promote items to active milestone.

</process>

<notes>

• 999.x numbering keeps backlog items out of the active phase sequence
• Phase directories are created immediately, so /gsd:discuss-phase and /gsd:plan-phase work on them
• No Depends on: field — backlog items are unsequenced by definition
• Sparse numbering is fine (999.1, 999.3) — always uses next-decimal

</notes>