Auto-trigger /gsd:verify-work when gsd-verifier returns human_needed status

[AshExplained]

Currently, when gsd-verifier completes with status: human_needed, it outputs a message saying "Human Verification Required" with test items, but the user must manually invoke /gsd:verify-work to actually perform the tests.

Current Behavior

/gsd:execute-phase N
│
└── gsd-verifier runs → status: human_needed
│
└── Outputs: "N items need human testing..."
└── User must manually run: /gsd:verify-work N

The verifier identifies items that need human verification and lists them in VERIFICATION.md, but does nothing to facilitate the actual testing.

Proposed Behavior

When gsd-verifier returns status: human_needed:

Option A (Prompt): Ask the user if they want to start UAT now

Human verification required for {N} items.
Would you like to run /gsd:verify-work now? [Y/n]

Option B (Auto-suggest with clear routing): Make the next step more prominent

━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
GSD ► HUMAN VERIFICATION REQUIRED
━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━

Automated checks passed but {N} items need human testing:

{Test name} — {what to verify}
{Test name} — {what to verify}
▶ /gsd:verify-work {N}

/clear first → fresh context window
━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━

Why This Matters

The human_needed status exists specifically because the verifier identified things it cannot check programmatically. Requiring manual invocation of /gsd:verify-work creates a gap where users might:

1. Miss the human verification items in the output
2. Proceed to the next phase without testing
3. Not realize the phase isn't truly verified

Affected Files

• commands/gsd/execute-phase.md — routing after verifier completes
• agents/gsd-verifier.md — output format for human_needed status
• get-shit-done/workflows/execute-phase.md — post-verification routing logic

[Tibsfox]

Submitted a fix for this in PR #823 — the `human_needed` handler in execute-phase.md now uses AskUserQuestion with three clear options:

1. Start /gsd:verify-work — run the UAT workflow (with /clear recommended for fresh context)
2. Mark all approved — skip manual testing and continue
3. Review verification report — see the full VERIFICATION.md first

This follows Option B from the issue (clear routing suggestion) since inline execution might run out of context on complex phases, and the user should be able to choose.

Complementary to PR #819 (browser pre-verification) — that PR makes the verification process smarter, while this fix makes the transition to verification automatic. They work well together if both land.