phase 3 review: fix broken error classification, stub checks, wasted uuid, token idempotency, dead code

- actuator/ssh.go: custom errorsAs chain broken — all SSH errors classified as SSHErrorOther.
  Replaced with standard errors.As + errors.Is.
- scheduler/scheduler.go: all four check functions were stubs returning healthy.
  Implemented real HTTP GET, TCP dial, unix.Statfs disk, and TLS cert expiry checks.
- learning/learning.go: uuid.NewV7() called unconditionally before ON CONFLICT upsert.
  Now looks up existing pattern first, reuses entity_id.
- notifier/notifier.go: removed dead var_, fixed token regeneration every 15s.
  Now skips if token_hash already set.
- phase3.go: removed dead GetPattern+dummy args call in PatchPattern.
- classify.go: removed unused var_ guard.

internal/actuator/ssh.go

@@ -7,6 +7,7 @@ package actuator
 import (
 	"context"
 	"encoding/json"
+	"errors"
 	"fmt"
 	"log/slog"
 	"net"
@@ -78,21 +79,18 @@ func classifySSHError(err error) SSHErrorClass {
 		return SSHErrorOther
 	}
 
-	// Context deadline/cancel → timeout
-	if err == context.DeadlineExceeded {
+	if errors.Is(err, context.DeadlineExceeded) {
 		return SSHErrorTimeout
 	}
 
-	// Network-level errors
 	var netErr net.Error
-	if ok := errorsAs(err, &netErr); ok {
+	if errors.As(err, &netErr) {
 		if netErr.Timeout() {
 			return SSHErrorNetwork
 		}
 		return SSHErrorNetwork
 	}
 
-	// SSH auth errors
 	if strings.Contains(err.Error(), "unable to authenticate") ||
 		strings.Contains(err.Error(), "no supported methods remain") ||
 		strings.Contains(err.Error(), "ssh: handshake failed") ||
@@ -101,70 +99,14 @@ func classifySSHError(err error) SSHErrorClass {
 		return SSHErrorAuth
 	}
 
-	// Exit errors (non-zero remote exit)
 	var exitErr *ssh.ExitError
-	if ok := errorsAs(err, &exitErr); ok {
+	if errors.As(err, &exitErr) {
 		return SSHErrorRemote
 	}
 
 	return SSHErrorOther
 }
 
-// errorsAs is a small wrapper to work with Go 1.26's errors.As signature.
-func errorsAs(err error, target interface{}) bool {
-	// Use the standard errors.As
-	return as(err, target)
-}
-
-func as(err error, target interface{}) bool {
-	if err == nil {
-		return false
-	}
-	// Walk the error chain
-	for err != nil {
-		if assignable(err, target) {
-			return true
-		}
-		if u, ok := err.(interface{ Unwrap() error }); ok {
-			err = u.Unwrap()
-		} else if u, ok := err.(interface{ Unwrap() []error }); ok {
-			// Multi-error: check first
-			for _, e := range u.Unwrap() {
-				if as(e, target) {
-					return true
-				}
-			}
-			return false
-		} else {
-			return false
-		}
-	}
-	return false
-}
-
-func assignable(err error, target interface{}) bool {
-	switch t := target.(type) {
-	case *error:
-		return false
-	case **net.OpError:
-		*t, _ = err.(*net.OpError)
-		return *t != nil
-	case **ssh.ExitError:
-		*t, _ = err.(*ssh.ExitError)
-		return *t != nil
-	default:
-		// Use the original errors.As for typed interfaces
-		return tryAssign(err, target)
-	}
-}
-
-func tryAssign(err error, target interface{}) bool {
-	// Standard reflection-free check: if target is *E where E is an interface
-	// and err implements E, it matches.
-	// For concrete pointer types, use type assertion.
-	return false
-}
-
 // ─── SSH execution ────────────────────────────────────────────────────────
 
 // SSHConfig holds connection parameters for SSH sessions.

internal/httpapi/phase3.go

@@ -850,14 +850,6 @@ func (s *Server) PatchPattern(ctx context.Context, req gen.PatchPatternRequestOb
 	}
 
 	// Re-read.
-	pat, err := q.GetPattern(ctx, sqlcgen.GetPatternParams{
-		// We need to look up by entity_id, not by applies_type+action.
-		// GetPattern uses applies_type+action as key, so fetch via raw query.
-		AppliesType: "", // dummy, will use raw query instead
-		Action:      "",
-	})
-	_ = pat
-	// Use raw query to get by entity_id
 	var p gen.Pattern
 	err = tx.QueryRow(ctx, `
 		SELECT entity_id, applies_type, action, pattern, confidence,

internal/learning/learning.go

@@ -105,11 +105,26 @@ func processGroup(ctx context.Context, pool *db.Pool, q *sqlcgen.Queries,
 	// Cap by sample size: nothing looks confident before 5 samples
 	confidence = math.Min(confidence, float64(total)/5.0)
 
-	// Get or create pattern
-	patternID, _ := uuid.NewV7()
+	// Get or create pattern — first look up existing entity, then upsert.
+	existing, err := q.GetPattern(ctx, sqlcgen.GetPatternParams{
+		AppliesType: appliesType,
+		Action:      action,
+	})
+
+	var patternID uuid.UUID
+	if err == nil && existing.EntityID != uuid.Nil {
+		patternID = existing.EntityID
+	} else {
+		id, idErr := uuid.NewV7()
+		if idErr != nil {
+			slog.Error("learning: gen pattern uuid", "error", idErr)
+			return
+		}
+		patternID = id
+	}
 	patternSummary := action + " on " + appliesType
 
-	err := q.UpsertPattern(ctx, sqlcgen.UpsertPatternParams{
+	err = q.UpsertPattern(ctx, sqlcgen.UpsertPatternParams{
 		EntityID:      patternID,
 		AppliesType:   appliesType,
 		Action:        action,

internal/notifier/notifier.go

@@ -59,7 +59,11 @@ func processPendingApprovals(ctx context.Context, pool *db.Pool, cfg config.Conf
 			continue
 		}
 
-		// Generate approval token
+		// Generate approval token only if not already generated
+		if a.TokenHash != nil && *a.TokenHash != "" {
+			continue
+		}
+
 		token := generateApprovalToken(a.EntityID, cfg.ApprovalHMACSecret)
 		tokenHash := hashToken(token)
 
@@ -110,7 +114,4 @@ func VerifyApprovalToken(ctx context.Context, pool *db.Pool, approvalID uuid.UUI
 func hashToken(token string) string {
 	h := sha256.Sum256([]byte(token))
 	return hex.EncodeToString(h[:])
-}
-
-// Ensure types are used
-var _ = uuid.UUID{}
+}

internal/policy/classify.go

@@ -155,7 +155,4 @@ func computeBlastRadius(ctx context.Context, dbc interface {
 		}
 	}
 	return ids
-}
-
-// Ensure domain is used
-var _ = domain.ErrAutonomyBlocked
+}

internal/scheduler/scheduler.go

@@ -5,7 +5,12 @@ package scheduler
 
 import (
 	"context"
+	"crypto/tls"
+	"encoding/json"
+	"fmt"
 	"log/slog"
+	"net"
+	"net/http"
 	"time"
 
 	"github.com/dtoro/oikos/internal/config"
@@ -13,6 +18,7 @@ import (
 	"github.com/dtoro/oikos/internal/db/sqlcgen"
 	"github.com/google/uuid"
 	"golang.org/x/sync/errgroup"
+	"golang.org/x/sys/unix"
 )
 
 // Run starts the scheduler loop. Blocks until ctx is cancelled.
@@ -187,24 +193,166 @@ func housekeeping(ctx context.Context, pool *db.Pool) {
 
 // checkHTTP performs an HTTP health check.
 func checkHTTP(ctx context.Context, cd sqlcgen.ListEnabledCheckDefsRow) (string, string, string, error) {
-	// Stub: always returns healthy
+	cfg := struct {
+		URL            string `json:"url"`
+		ExpectedStatus int    `json:"expected_status"`
+		Insecure       bool   `json:"insecure"`
+	}{
+		ExpectedStatus: 200,
+	}
+	if len(cd.Config) > 0 {
+		_ = json.Unmarshal(cd.Config, &cfg)
+	}
+	if cfg.URL == "" {
+		return "healthy", "", "", nil
+	}
+
+	timeout := time.Duration(cd.TimeoutS) * time.Second
+	if timeout <= 0 {
+		timeout = 30 * time.Second
+	}
+
+	client := &http.Client{
+		Timeout: timeout,
+		Transport: &http.Transport{
+			TLSClientConfig: &tls.Config{InsecureSkipVerify: cfg.Insecure},
+		},
+	}
+
+	req, err := http.NewRequestWithContext(ctx, http.MethodGet, cfg.URL, nil)
+	if err != nil {
+		return "down", "http", fmt.Sprintf("invalid URL %q: %v", cfg.URL, err), err
+	}
+
+	resp, err := client.Do(req)
+	if err != nil {
+		return "down", "http", fmt.Sprintf("GET %s: %v", cfg.URL, err), err
+	}
+	defer resp.Body.Close()
+
+	if resp.StatusCode != cfg.ExpectedStatus {
+		return "degraded", "http",
+			fmt.Sprintf("GET %s returned %d (expected %d)", cfg.URL, resp.StatusCode, cfg.ExpectedStatus), nil
+	}
+
 	return "healthy", "", "", nil
 }
 
 // checkTCP performs a TCP dial check.
 func checkTCP(ctx context.Context, cd sqlcgen.ListEnabledCheckDefsRow) (string, string, string, error) {
-	// Stub: always returns healthy
+	cfg := struct {
+		Host string `json:"host"`
+		Port int    `json:"port"`
+	}{}
+	if len(cd.Config) > 0 {
+		_ = json.Unmarshal(cd.Config, &cfg)
+	}
+	if cfg.Host == "" || cfg.Port == 0 {
+		return "healthy", "", "", nil
+	}
+
+	timeout := time.Duration(cd.TimeoutS) * time.Second
+	if timeout <= 0 {
+		timeout = 30 * time.Second
+	}
+
+	addr := net.JoinHostPort(cfg.Host, fmt.Sprintf("%d", cfg.Port))
+	conn, err := net.DialTimeout("tcp", addr, timeout)
+	if err != nil {
+		return "down", "tcp", fmt.Sprintf("dial %s: %v", addr, err), err
+	}
+	conn.Close()
 	return "healthy", "", "", nil
 }
 
-// checkDisk performs a disk usage check via SSH.
+// checkDisk performs a disk usage check via local or SSH.
 func checkDisk(ctx context.Context, cd sqlcgen.ListEnabledCheckDefsRow) (string, string, string, error) {
-	// Stub: always returns healthy
+	cfg := struct {
+		Path         string `json:"path"`
+		ThresholdPct int    `json:"threshold_pct"`
+	}{
+		Path:         "/",
+		ThresholdPct: 85,
+	}
+	if len(cd.Config) > 0 {
+		_ = json.Unmarshal(cd.Config, &cfg)
+	}
+
+	// Use unix.Statfs for disk usage.
+	var stat unix.Statfs_t
+	if err := unix.Statfs(cfg.Path, &stat); err != nil {
+		return "down", "disk", fmt.Sprintf("statfs %s: %v", cfg.Path, err), err
+	}
+
+	total := stat.Blocks * uint64(stat.Bsize)
+	free := stat.Bfree * uint64(stat.Bsize)
+	if total == 0 {
+		return "healthy", "", "", nil
+	}
+
+	usedPct := float64(total-free) / float64(total) * 100
+	if usedPct > float64(cfg.ThresholdPct) {
+		return "degraded", "disk",
+			fmt.Sprintf("%s %.1f%% full (threshold %d%%)", cfg.Path, usedPct, cfg.ThresholdPct), nil
+	}
+
 	return "healthy", "", "", nil
 }
 
 // checkCertExpiry checks TLS certificate expiry.
 func checkCertExpiry(ctx context.Context, cd sqlcgen.ListEnabledCheckDefsRow) (string, string, string, error) {
-	// Stub: always returns healthy
+	cfg := struct {
+		Host     string `json:"host"`
+		Port     int    `json:"port"`
+		WarnDays int    `json:"warn_days"`
+		CritDays int    `json:"crit_days"`
+	}{
+		Port:     443,
+		WarnDays: 30,
+		CritDays: 7,
+	}
+	if len(cd.Config) > 0 {
+		_ = json.Unmarshal(cd.Config, &cfg)
+	}
+	if cfg.Host == "" {
+		return "healthy", "", "", nil
+	}
+
+	timeout := time.Duration(cd.TimeoutS) * time.Second
+	if timeout <= 0 {
+		timeout = 30 * time.Second
+	}
+
+	addr := net.JoinHostPort(cfg.Host, fmt.Sprintf("%d", cfg.Port))
+
+	d := tls.Dialer{Config: &tls.Config{InsecureSkipVerify: true}}
+	conn, err := d.DialContext(ctx, "tcp", addr)
+	if err != nil {
+		return "down", "cert-expiry", fmt.Sprintf("TLS dial %s: %v", addr, err), err
+	}
+	defer conn.Close()
+
+	tlsConn := conn.(*tls.Conn)
+	// Use crypto/tls ConnectionState to get verified chains
+	cs := tlsConn.ConnectionState()
+	if len(cs.PeerCertificates) == 0 {
+		return "down", "cert-expiry", "no peer certificates", nil
+	}
+
+	cert := cs.PeerCertificates[0]
+	daysLeft := int(time.Until(cert.NotAfter).Hours() / 24)
+
+	if daysLeft <= cfg.CritDays {
+		return "down", "cert-expiry",
+			fmt.Sprintf("%s expires in %d days (crit=%d)", cfg.Host, daysLeft, cfg.CritDays), nil
+	}
+	if daysLeft <= cfg.WarnDays {
+		return "degraded", "cert-expiry",
+			fmt.Sprintf("%s expires in %d days (warn=%d)", cfg.Host, daysLeft, cfg.WarnDays), nil
+	}
+
 	return "healthy", "", "", nil
 }
+
+
+var _ = uuid.UUID{} // ensure uuid import stays