Extract config structs into pkg/probodconfig

probod-bootstrap only needs the config struct definitions for
YAML marshaling but transitively pulled in ~40 heavy runtime
dependencies via pkg/probod. Move all config types and their
methods to a new pkg/probodconfig package and re-export them
from pkg/probod via type aliases for backward compatibility.

Signed-off-by: Émile Ré <emile@getprobo.com>

pkg/probodconfig/connector_config.go

@@ -0,0 +1,98 @@
+// Copyright (c) 2026 Probo Inc <hello@getprobo.com>.
+//
+// Permission to use, copy, modify, and/or distribute this software for any
+// purpose with or without fee is hereby granted, provided that the above
+// copyright notice and this permission notice appear in all copies.
+//
+// THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES WITH
+// REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
+// AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT,
+// INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
+// LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR
+// OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
+// PERFORMANCE OF THIS SOFTWARE.
+
+package probodconfig
+
+import (
+	"bytes"
+	"encoding/json"
+	"fmt"
+	"strings"
+
+	"go.probo.inc/probo/pkg/connector"
+)
+
+type ConnectorConfig struct {
+	Provider    string                 `json:"provider"`
+	Protocol    connector.ProtocolType `json:"protocol"`
+	Config      connector.Connector    `json:"-"`
+	RawConfig   any                    `json:"config,omitempty"`
+	Settings    any                    `json:"-"`
+	RawSettings any                    `json:"settings,omitempty"`
+}
+
+type ConnectorConfigOAuth2 struct {
+	ClientID     string `json:"client-id"`
+	ClientSecret string `json:"client-secret"`
+}
+
+func (c *Config) GetSlackSigningSecret() string {
+	if c.Notifications.Slack.SigningSecret != "" {
+		return c.Notifications.Slack.SigningSecret
+	}
+
+	for _, conn := range c.Connectors {
+		if conn.Provider == "SLACK" {
+			if settings, ok := conn.Settings.(map[string]any); ok {
+				if signingSecret, ok := settings["signing-secret"].(string); ok {
+					return signingSecret
+				}
+			}
+		}
+	}
+	return ""
+}
+
+func (c *ConnectorConfig) UnmarshalJSON(data []byte) error {
+	var tmp struct {
+		Provider  string          `json:"provider"`
+		Protocol  string          `json:"protocol"`
+		RawConfig json.RawMessage `json:"config"`
+		Settings  json.RawMessage `json:"settings"`
+	}
+
+	if err := json.NewDecoder(bytes.NewReader(data)).Decode(&tmp); err != nil {
+		return fmt.Errorf("cannot unmarshal connector config: %w", err)
+	}
+
+	c.Provider = strings.ToUpper(tmp.Provider)
+	c.Protocol = connector.ProtocolType(strings.ToUpper(tmp.Protocol))
+
+	if len(tmp.Settings) > 0 {
+		var settings map[string]any
+		if err := json.NewDecoder(bytes.NewReader(tmp.Settings)).Decode(&settings); err != nil {
+			return fmt.Errorf("cannot unmarshal settings: %w", err)
+		}
+		c.Settings = settings
+	}
+
+	switch c.Protocol {
+	case connector.ProtocolOAuth2:
+		var config ConnectorConfigOAuth2
+		if err := json.NewDecoder(bytes.NewReader(tmp.RawConfig)).Decode(&config); err != nil {
+			return fmt.Errorf("cannot unmarshal oauth2 connector config: %w", err)
+		}
+
+		oauth2Connector := connector.OAuth2Connector{
+			ClientID:     config.ClientID,
+			ClientSecret: config.ClientSecret,
+		}
+
+		c.Config = &oauth2Connector
+	default:
+		return fmt.Errorf("unknown connector protocol: %q", c.Protocol)
+	}
+
+	return nil
+}