refactor(actions): small cleanups across models, services and routers (#39722)

Collection of small, behaviour-preserving cleanups in the Actions code.

- Fix log and error prefixes that named non-existent or wrong functions,
and wrap errors with `%w` so `errors.Is` keeps working.
- Remove unused code.
- Rely on `ctx.ServerError` / `ctx.APIErrorAuto`, which already map
`util.ErrNotExist` and friends, instead of equivalent hand-written
switches.
- Load runs referenced by commit statuses with one query instead of one
per run (used on every PR view); the result order is now stable.
- Encode an event's payload once instead of up to three times.
- Share the duplicated runner-token "get or create" logic and the
"notify and emit" call pair.
- Simplify `ToActionArtifact` / `ToActionRunner` signatures.

---------

Signed-off-by: bircni <bircni@icloud.com>
Co-authored-by: delvh <dev.lh@web.de>
Co-authored-by: wxiaoguang <wxiaoguang@gmail.com>

models/actions/runner_token.go

@@ -5,6 +5,7 @@ package actions
 
 import (
 	"context"
+	"errors"
 	"fmt"
 
 	"gitea.dev/models/db"
@@ -119,3 +120,12 @@ func GetLatestRunnerToken(ctx context.Context, ownerID, repoID int64) (*ActionRu
 	}
 	return &runnerToken, nil
 }
+
+// GetOrCreateActiveRunnerToken returns the latest runner token, or a new one if there is none or it is no longer active
+func GetOrCreateActiveRunnerToken(ctx context.Context, ownerID, repoID int64) (*ActionRunnerToken, error) {
+	token, err := GetLatestRunnerToken(ctx, ownerID, repoID)
+	if errors.Is(err, util.ErrNotExist) || (token != nil && !token.IsActive) {
+		return NewRunnerToken(ctx, ownerID, repoID)
+	}
+	return token, err
+}