refactor: remove unreachable runner code (#1179)

Remove inherited act APIs, configuration branches, and test seams that neither the daemon nor exec can reach. Constant-fold settings both entry points already enforce and consolidate duplicate runner paths.

Major removals:

- Unwired custom action-cache and local-repository-cache implementations.
- Legacy matrix, platform, input, container-reuse, logging, Git remote, and action-replacement configuration paths.
- Unused Docker socket, container network, tar-copy, and platform PTY wrappers.
- Single-implementation filesystem, environment, runner, and expression abstractions.
- Duplicated step-container, command-logging, credential, reusable-workflow, and execution paths.
- Generated client mock boilerplate, obsolete fixtures, test-only seams, stale wrappers, and commented-out code.

This removes 2844 net Go lines while retaining Gitea RPC, event, matrix, input, cache, artifact, action, reusable workflow, Docker, host, exec, and release behavior.

Assisted by Codex (GPT-5).

Reviewed-on: https://gitea.com/gitea/runner/pulls/1179
Reviewed-by: bircni <bircni@icloud.com>
Co-authored-by: silverwind <me@silverwind.io>

internal/pkg/client/http.go

@@ -14,6 +14,7 @@ import (
 
 	"connectrpc.com/connect"
 	"gitea.dev/actionslib/ping/v1/pingv1connect"
+	"gitea.dev/actionslib/pkg/protocol"
 	"gitea.dev/actionslib/runner/v1/runnerv1connect"
 )
 
@@ -42,10 +43,10 @@ func New(endpoint string, insecure bool, uuid, token string, timeout time.Durati
 		return func(ctx context.Context, req connect.AnyRequest) (connect.AnyResponse, error) {
 			req.Header().Set("User-Agent", "gitea-runner/"+ver.Version())
 			if uuid != "" {
-				req.Header().Set(UUIDHeader, uuid)
+				req.Header().Set(protocol.UUIDHeader, uuid)
 			}
 			if token != "" {
-				req.Header().Set(TokenHeader, token)
+				req.Header().Set(protocol.TokenHeader, token)
 			}
 			return next(ctx, req)
 		}
@@ -64,7 +65,6 @@ func New(endpoint string, insecure bool, uuid, token string, timeout time.Durati
 			opts...,
 		),
 		endpoint: endpoint,
-		insecure: insecure,
 	}
 }
 
@@ -72,10 +72,6 @@ func (c *HTTPClient) Address() string {
 	return c.endpoint
 }
 
-func (c *HTTPClient) Insecure() bool {
-	return c.insecure
-}
-
 var _ Client = (*HTTPClient)(nil)
 
 // An HTTPClient manages communication with the runner API.
@@ -83,5 +79,4 @@ type HTTPClient struct {
 	pingv1connect.PingServiceClient
 	runnerv1connect.RunnerServiceClient
 	endpoint string
-	insecure bool
 }