nomos+web: streaming, provider routing, event gap-fill, embedded UI; fix approval FK & session context

Agent (cmd/nomos):
- Stream LLM tokens via NewStreaming; emit text_delta then final text.
- OpenRouter provider routing: data_collection=deny (ZDR) + require_parameters;
  NOMOS_PROVIDER_SORT opt-in; Exacto via model suffix.
- Multi-turn: reload session history into context; UI passes session id.
- Fix agent_activity logging (agent_id/session_id) and mcpClient data race.

Events (live control-room feed):
- approval.created (mcp), approval.decided (api), execution.completed/failed
  (approved-action path), signal.raised/resolved + health.changed (scheduler,
  transition-gated).

Fixes:
- createApproval FK violation (reuse execution entity) — the agent's only
  write path; log the previously-swallowed errors.

Web UI:
- Embed web/dist via //go:embed (single binary); Dockerfile builds SPA into
  the Go stage; committed .gitkeep placeholder keeps backend-only builds green.
- Caddy: Authentik-gated /agent/* -> nomos so the UI reaches the agent
  same-origin in production.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

go.mod

@@ -8,11 +8,14 @@ require (
 	github.com/golang-jwt/jwt/v5 v5.3.1
 	github.com/google/jsonschema-go v0.4.3
 	github.com/google/uuid v1.6.0
+	github.com/infisical/go-sdk v0.8.0
 	github.com/jackc/pgx/v5 v5.10.0
 	github.com/modelcontextprotocol/go-sdk v1.6.1
 	github.com/oapi-codegen/runtime v1.4.2
+	github.com/openai/openai-go v1.12.0
 	golang.org/x/crypto v0.53.0
 	golang.org/x/sync v0.21.0
+	golang.org/x/sys v0.46.0
 	gopkg.in/yaml.v3 v3.0.1
 )
 
@@ -47,7 +50,6 @@ require (
 	github.com/googleapis/enterprise-certificate-proxy v0.3.11 // indirect
 	github.com/googleapis/gax-go/v2 v2.17.0 // indirect
 	github.com/hashicorp/golang-lru/v2 v2.0.7 // indirect
-	github.com/infisical/go-sdk v0.8.0 // indirect
 	github.com/jackc/pgpassfile v1.0.0 // indirect
 	github.com/jackc/pgservicefile v0.0.0-20240606120523-5a60cdf6a761 // indirect
 	github.com/jackc/puddle/v2 v2.2.2 // indirect
@@ -60,6 +62,10 @@ require (
 	github.com/segmentio/asm v1.1.3 // indirect
 	github.com/segmentio/encoding v0.5.4 // indirect
 	github.com/sony/gobreaker v0.5.0 // indirect
+	github.com/tidwall/gjson v1.14.4 // indirect
+	github.com/tidwall/match v1.1.1 // indirect
+	github.com/tidwall/pretty v1.2.1 // indirect
+	github.com/tidwall/sjson v1.2.5 // indirect
 	github.com/yosida95/uritemplate/v3 v3.0.2 // indirect
 	github.com/youmark/pkcs8 v0.0.0-20240726163527-a2c0da244d78 // indirect
 	go.opentelemetry.io/auto/sdk v1.2.1 // indirect
@@ -70,7 +76,6 @@ require (
 	go.opentelemetry.io/otel/trace v1.39.0 // indirect
 	golang.org/x/net v0.55.0 // indirect
 	golang.org/x/oauth2 v0.35.0 // indirect
-	golang.org/x/sys v0.46.0 // indirect
 	golang.org/x/text v0.38.0 // indirect
 	golang.org/x/time v0.14.0 // indirect
 	google.golang.org/api v0.267.0 // indirect