Connector tools: on by default for the owner's own use of every Bot, also on shared Bots; other people's use is a separate opt-in #369

Follow-up to #335 / #346 (per-Bot connector switch), changing its default and its rule for shared Bots. This records the owner's decision.

What the user said

Looking at Settings > Connectors > Composio > Choose Bots (every Bot off; shared Bots greyed out as "Unavailable: shared with Friend (@friend.home)" with a disabled switch):

这个都应该是默认打开的，并且bot共享了之后自己应该也能用，设置的应该是默认别人不能用，但是可以打开

(Translation: these should all be on by default; and after a Bot is shared, the owner must still be able to use it; the setting should be "others cannot use it by default, but you can turn it on".)

Problem

#346 made connector tools off by default for every Bot and never available on a shared Bot (the switch was disabled and a grant cleared it). Result: after upgrading, the owner's own Bots lose the connector they just connected, and sharing a Bot (a grant, a friend, a face room, a room code) takes the owner's own use away too.

Decision (supersedes that part of #346)

1. A connected connector is on by default for the owner's own use of every Bot: new Bots, existing Bots after the upgrade, and Bots that already had no flag. Only an explicit off stays off.
2. A Bot that is shared is still usable by its owner with the connector tools.
3. Other people's use is a separate per-Bot, per-connector switch, off by default and never disabled; the owner can turn it on ("also when others use it"). Others means: a friend, another room member, another owner's Bot, or a turn in a room with other people in it.
4. Who is driving a turn is decided at call time from the messages the turn took in, not from the Bot's own words. If it cannot be determined, it counts as someone else's (fail closed).

Unchanged from #346: the Composio session address stays out of state.json; an Agent or parent chain that cannot be resolved gets no connector tools; hidden tool lists refresh when switches, sharing or the turn's origin change; the DSH Agent and plain DSH sessions keep the tools.