fix: preserve custom lead agent names during reprovisioning

[aramirez087]

Summary

• Lead agent names set via PATCH (e.g. "Ferris", "Sentinel") were silently reverted to "Lead Agent" on every lifecycle reconciliation
• Root cause: ensure_board_lead_agent() always fell back to the static default name when config_options.agent_name was None (which it is during automated reprovisions)
• Fix: prefer the agent's existing DB name over the static default

The bug

# Before: always resets to "Lead Agent" during reprovisioning
desired_name = config_options.agent_name or self.lead_agent_name(board)

Every gateway restart, heartbeat config patch, or lifecycle reconciliation would overwrite custom names. In practice this meant renamed agents reverted within minutes.

The fix

# After: preserves existing custom name
default_name = self.lead_agent_name(board)
desired_name = config_options.agent_name or existing.name or default_name

Fallback chain: explicit config name > existing DB name > "Lead Agent" (new agents only).

Test plan

• make backend-test — 469 passed, 0 failed
• Rename a lead agent via PATCH, trigger a reprovision, verify name persists
• Create a new board lead — verify it still defaults to "Lead Agent"

🤖 Generated with Claude Code

[Copilot]

Pull request overview

Fixes a provisioning reconciliation bug in the OpenClaw DB provisioning service where board lead agent display names set via PATCH were being overwritten back to the static default during reprovisioning.

Changes:

• Updates ensure_board_lead_agent() to prefer the existing persisted lead agent name when no explicit agent_name override is provided.
• Keeps the static default lead agent name as the fallback for newly created lead agents.