Enable AI Governance dashboard flags by default

Turns on three AI Governance dashboard feature flags by default, so the 19.5 cards and filters ship to everyone. Each flag moves from wip to beta with a rollout issue.

SkillGuard is not part of this rollout. ai_governance_skillguard_widget stays off by default, because nothing reports SkillGuard findings on customer projects yet.

Changes

• ai_governance_tool_calls: the tool calls tile, and the Top tools used by agents and Tool calls by risk cards. Rollout: #632775+s
• ai_governance_dashboard_charts: the Which AI agents developers are using card. Rollout: #632776+s
• ai_governance_connected_agents_filter: the All agents and Connected options. Its group changes from group::compliance to group::ai governance, the group that owns it. Rollout: #632777+s

Screenshots

Production test group, last 30 days, All agents. Before is what a group without these flags sees today.

	Before	After
Summary tiles	Agents and sessions tiles only
Show control	DAP only
Tool calls by risk	Not shown
Top tools used by agents	Not shown
Which AI agents developers are using	Not shown

Before merge

• ai_governance_sessions_api is on by default (Enable ai_governance_sessions_api by default (!259993 - merged)). The Connected views need it, because connected agents only write to the sessions table.
• Verified on the test group: the tool calls tile and cards and the agents card match the API.

Out of scope

• ai_governance_skillguard_widget stays wip.
• Instances without ClickHouse show the empty state on the tool calls cards and the agents card.