Authenticate with a seeded operator key; fold escalation and switches into TerdutTeam

Credentials: the TerdutServer controller generates <name>-operator-key in
the server's own namespace (owned by it) and hands it to the pods as
TERDUT_OPERATOR_KEY; the server creates its instance-scoped account from it
at every start. A replaced Secret rolls the pods. The bootstrap handshake,
the checkpoint Secret, per-team service accounts and credentials Secrets,
BootstrapStateLost and credentials.deletionPolicy are gone.

CRDs: TerdutServer, TerdutTeam and TerdutAlertSource. TerdutEscalationRule
and TerdutDeadmanSwitch become spec.escalation and spec.deadmanSwitches[]
on the team (matched by name, extras removed); team invites are removed.
A team is created under the identity <namespace>/<name> (external_id), so a
retry, a lost status or a deleted team heal by repeating the same call, and
a display name owned by another team is TeamNameTaken instead of an
adoption. The server resolves escalation usernames (UnknownUser condition).
OIDC claim names and trustEmail are spec fields.

Fixes: query values are URL-escaped; every delete treats 404 as success;
deleting a team no longer depends on allowedTeams consent; a switch or
integration deleted on the server is recreated; unnamed switches take the
CR's name.

Cleanup: scaffold e2e test, AGENTS.md, devcontainer, unused config/ pieces
and Client.Version() removed; DESIGN.md, README, ROADMAP and the demo
(run-demo.sh, manifests) rewritten for the new design. Secret RBAC stays
cluster-wide, now stated in DESIGN.md section 9.

Claude-Session: https://claude.ai/code/session_016mBLURvJoMuUEr9cB2RpUN

config/rbac/role.yaml

@@ -68,8 +68,6 @@ rules:
   - terdut.ryuvia.com
   resources:
   - terdutalertsources
-  - terdutdeadmanswitches
-  - terdutescalationrules
   - terdutservers
   - terdutteams
   verbs:
@@ -84,8 +82,6 @@ rules:
   - terdut.ryuvia.com
   resources:
   - terdutalertsources/finalizers
-  - terdutdeadmanswitches/finalizers
-  - terdutescalationrules/finalizers
   - terdutservers/finalizers
   - terdutteams/finalizers
   verbs:
@@ -94,8 +90,6 @@ rules:
   - terdut.ryuvia.com
   resources:
   - terdutalertsources/status
-  - terdutdeadmanswitches/status
-  - terdutescalationrules/status
   - terdutservers/status
   - terdutteams/status
   verbs: