Whenever running on a platform that has a TPM (and tailscaled can access
it), default to encrypting the state. The user can still explicitly set
this flag to disable encryption.
Updates https://github.com/tailscale/corp/issues/32909
Signed-off-by: Andrew Lytvynov <awly@tailscale.com>
Saves 139 KB.
Also Synology support, which I saw had its own large-ish proxy parsing
support on Linux, but support for proxies without Synology proxy
support is reasonable, so I pulled that out as its own thing.
Updates #12614
Change-Id: I22de285a3def7be77fdcf23e2bec7c83c9655593
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>