feat(observability): restore monitoring coverage, make gaps visible, stream executions

Monitoring coverage was 3 of 89 active entities. Three bugs, each hidden by
discarded errors in checkdefaults:

- writeCheck generated a fresh uuid, inserted the check entity ON CONFLICT
  (slug) DO NOTHING, then wrote a check_defs row referencing it. On any
  re-seed the slug already existed, the entity insert no-oped, and the FK
  violated — aborting the ingest transaction and surfacing as an unrelated
  failure several entities later. Re-seeding has been broken since; prod's
  coverage was frozen at its first successful seed. This is what
  TestSeedIngestIdempotentAndNoDuplicateEdges had been reporting.
- shortSlug truncated to the last 8 chars, so all 21 ingress routes collapsed
  to ".network" and overwrote each other; service:jellyfin collided with
  lxc:jellyfin.
- The ssh-script checker never read the `args` config checkdefaults wrote, so
  process_check.sh always ran without its unit name and returned "unknown".

Coverage is now 75/89. Monitoring is declared per entity type in
seeds/ontology.yaml and resolved through the is-a hierarchy, so a type can say
it warrants nothing (site, lan, mesh, cluster) and never be reported as a gap.
coverageSweep raises an `unmonitored` signal only where a type declares
monitoring it lacks — 8 real gaps, no false positives.

Also:
- entity_types.attribute_schema was never ingested: the seed loader read
  "attribute_schema" but the YAML says "attributes", so all 60 types stored
  JSON null.
- ListExecutions ignored its declared target/action/correlation_id filters and
  paginated on a non-unique target slug, dropping and repeating rows.
- started_at was captured but only written at terminal state, so a running
  execution reported NULL for its whole life. The three MCP auto-run copies
  wrote no timing at all; they are now one autoRun helper.
- SSH output was buffered to completion and discarded entirely on timeout.
  Both sshExec copies now stream through a shared execlog sink into
  execution_logs, and keep partial output when a command is cancelled.
- executions.correlation_id was a random per-execution uuid that correlated
  nothing; it is now the chat session id, which is what lets the chat tail
  live output.
- reversible_low had no auto-run branch despite policy declaring it
  unattended. Since computeCommandRisk never returns it, the class only arises
  when an agent declares it over a read_only command — so gating it penalised
  candor without adding safety.
- backup-target gains a backup-freshness checker (portable find -mmin, since
  the first target is on macOS), resolving its host by walking backs-up-to
  backwards. The pre-deploy pg_dump is now a tracked backup target.

UI: an Executions section on entity detail with live output tailing, and
streamed output under a running `run` call in the chat timeline.

Migrations 022-024. Ops.svelte and context.ts exclude execution.output from
their refetch triggers, which would otherwise fire once a second per command.

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

internal/scheduler/scheduler.go

@@ -16,6 +16,7 @@ import (
 	"regexp"
 	"runtime"
 	"strconv"
+	"strings"
 	"time"
 
 	"github.com/dtoro/oikos/internal/config"
@@ -73,7 +74,12 @@ func runCheckPass(ctx context.Context, pool *db.Pool) {
 		return
 	}
 	if len(defs) == 0 {
+		// Still run housekeeping: a fleet with no enabled check_defs is
+		// precisely the case coverageSweep exists to report, and returning
+		// here would mean the one situation that most needs reporting is the
+		// one situation that stays silent.
 		slog.Debug("scheduler: no enabled check_defs")
+		housekeeping(ctx, pool)
 		return
 	}
 
@@ -248,6 +254,8 @@ func executeCheck(ctx context.Context, cd sqlcgen.ListEnabledCheckDefsRow) check
 		return checkPing(ctx, cd)
 	case "ssh-script":
 		return checkSSHScript(ctx, cd)
+	case "backup-freshness":
+		return checkBackupFreshness(ctx, cd)
 	default:
 		return checkResult{health: "unknown"}
 	}
@@ -265,6 +273,7 @@ func housekeeping(ctx context.Context, pool *db.Pool) {
 	}
 
 	staleSweep(ctx, pool)
+	coverageSweep(ctx, pool)
 
 	// Log housekeeping completion
 	slog.Debug("scheduler: housekeeping done", "pruned_idempotency_before", cutoff.Format(time.RFC3339))
@@ -337,9 +346,14 @@ func checkHTTP(ctx context.Context, cd sqlcgen.ListEnabledCheckDefsRow) checkRes
 	cfg := struct {
 		URL            string `json:"url"`
 		ExpectedStatus int    `json:"expected_status"`
-		Insecure       bool   `json:"insecure"`
+		// MaxStatus accepts a range instead of one exact code. Most services
+		// sit behind Authentik and answer 302 or 401 — a working service, but
+		// an exact-match on 200 reports it degraded and raises a signal.
+		// Unset expected_status means "any response below MaxStatus is fine".
+		MaxStatus int  `json:"max_status"`
+		Insecure  bool `json:"insecure"`
 	}{
-		ExpectedStatus: 200,
+		MaxStatus: 500,
 	}
 	if len(cd.Config) > 0 {
 		_ = json.Unmarshal(cd.Config, &cfg)
@@ -379,10 +393,17 @@ func checkHTTP(ctx context.Context, cd sqlcgen.ListEnabledCheckDefsRow) checkRes
 	}
 	defer resp.Body.Close()
 
-	if resp.StatusCode != cfg.ExpectedStatus {
+	if cfg.ExpectedStatus != 0 {
+		if resp.StatusCode != cfg.ExpectedStatus {
+			return checkResult{
+				health: "degraded", signalKind: "http",
+				evidence: fmt.Sprintf("GET %s returned %d (expected %d)", cfg.URL, resp.StatusCode, cfg.ExpectedStatus),
+			}
+		}
+	} else if resp.StatusCode >= cfg.MaxStatus {
 		return checkResult{
 			health: "degraded", signalKind: "http",
-			evidence: fmt.Sprintf("GET %s returned %d (expected %d)", cfg.URL, resp.StatusCode, cfg.ExpectedStatus),
+			evidence: fmt.Sprintf("GET %s returned %d (expected below %d)", cfg.URL, resp.StatusCode, cfg.MaxStatus),
 		}
 	}
 
@@ -616,6 +637,11 @@ func checkSSHScript(ctx context.Context, cd sqlcgen.ListEnabledCheckDefsRow) che
 		Port   int    `json:"port"`
 		User   string `json:"user"`
 		Script string `json:"script"`
+		// Args is a single positional argument for the script. checkdefaults
+		// has always written it for process_check.sh, but nothing read it —
+		// so every process check ran argument-less and process_check.sh
+		// answered "no service name provided" with health unknown.
+		Args string `json:"args"`
 	}{}
 	if len(cd.Config) > 0 {
 		_ = json.Unmarshal(cd.Config, &cfg)
@@ -646,6 +672,11 @@ func checkSSHScript(ctx context.Context, cd sqlcgen.ListEnabledCheckDefsRow) che
 	defer cancel()
 
 	scriptPath := "/opt/oikos/checks/" + cfg.Script
+	if cfg.Args != "" {
+		// Single-quote the argument so an entity name can never break out of
+		// the remote command. The script name itself is allowlisted above.
+		scriptPath += " '" + strings.ReplaceAll(cfg.Args, "'", `'\''`) + "'"
+	}
 	port := strconv.Itoa(cfg.Port)
 
 	output, err := sshExec(ctx, cfg.Host, port, cfg.User, scriptPath, timeout)