refactor(workspace-remote): split WorkspaceRemoteSessionController by concern

WorkspaceRemoteSession.swift (2582 lines) held a single class,
WorkspaceRemoteSessionController, whose ~100 methods spanned five
unrelated concerns. Split along those seams into extension files, moving
every method verbatim:

- WorkspaceRemoteSessionController+ConnectionOrchestration.swift:
  connection-attempt/reverse-relay/proxy-lease orchestration and status
  publishing (stopAllLocked...stopReverseRelayViaControlMasterLocked,
  plus the bootstrapRemoteTTYRetry* constants).
- WorkspaceRemoteSessionController+ProcessExecution.swift: ssh/scp
  argument assembly and the underlying Process execution primitive
  (sshCommonArguments...runProcess).
- WorkspaceRemoteSessionController+DaemonInstall.swift: remote daemon
  bootstrap/build/download/upload and dropped-file upload
  (bootstrapDaemonLocked...helloRemoteDaemonLocked, plus the
  remotePlatformProbe* markers and remoteDaemonManifestInfoKey).
- WorkspaceRemoteSessionController+ScriptBuilders.swift: debug logging,
  remote shell script builders, and process/PID utilities
  (debugLog...shouldEscalateProxyErrorToBootstrap, plus
  cachedRemoteDaemonSourceFingerprint).
- WorkspaceRemoteSessionController+PortScanning.swift: remote
  listening-port scan scheduling, polling, and script builders
  (updateRemotePortScanTTYs...remoteAllPortsScanScript).

WorkspaceRemoteSession.swift itself now holds only the class declaration,
its nested types, stored properties, init, and the start/stop/
uploadDroppedFiles entry points.

Access-level widening: every member of WorkspaceRemoteSessionController
(nested types, stored properties, and ~100 methods) was declared
private, which in Swift restricts visibility to the declaring file. To
split the class into extensions across files, all of these were widened
from private to the Swift default internal access level -- still
module-scoped, not exposed outside the app target. This is a blanket,
mechanical widening across the whole type rather than an itemized one
(the type's entire private surface needed it to support the split),
verified behavior-identical by a non-blank-line multiset diff against
the pre-split file before committing.

project.pbxproj updated: five new extension files registered (main app
target only).

Refs #98.

Author: arzafran

GhosttyTabs.xcodeproj/project.pbxproj

@@ -53,6 +53,11 @@
 		A5001405 /* PanelContentView.swift in Sources */ = {isa = PBXBuildFile; fileRef = A5001415 /* PanelContentView.swift */; };
 		A5001406 /* Workspace.swift in Sources */ = {isa = PBXBuildFile; fileRef = A5001416 /* Workspace.swift */; };
 		A5FF0012 /* WorkspaceRemoteSession.swift in Sources */ = {isa = PBXBuildFile; fileRef = A5FF0002 /* WorkspaceRemoteSession.swift */; };
+		NRWS00000000000000000018 /* WorkspaceRemoteSessionController+ConnectionOrchestration.swift in Sources */ = {isa = PBXBuildFile; fileRef = NRWS00000000000000000017 /* WorkspaceRemoteSessionController+ConnectionOrchestration.swift */; };
+		NRWS00000000000000000020 /* WorkspaceRemoteSessionController+ProcessExecution.swift in Sources */ = {isa = PBXBuildFile; fileRef = NRWS00000000000000000019 /* WorkspaceRemoteSessionController+ProcessExecution.swift */; };
+		NRWS00000000000000000022 /* WorkspaceRemoteSessionController+DaemonInstall.swift in Sources */ = {isa = PBXBuildFile; fileRef = NRWS00000000000000000021 /* WorkspaceRemoteSessionController+DaemonInstall.swift */; };
+		NRWS00000000000000000024 /* WorkspaceRemoteSessionController+ScriptBuilders.swift in Sources */ = {isa = PBXBuildFile; fileRef = NRWS00000000000000000023 /* WorkspaceRemoteSessionController+ScriptBuilders.swift */; };
+		NRWS00000000000000000026 /* WorkspaceRemoteSessionController+PortScanning.swift in Sources */ = {isa = PBXBuildFile; fileRef = NRWS00000000000000000025 /* WorkspaceRemoteSessionController+PortScanning.swift */; };
 		NRWS00000000000000000006 /* WorkspaceRemoteDaemonPendingCallRegistry.swift in Sources */ = {isa = PBXBuildFile; fileRef = NRWS00000000000000000005 /* WorkspaceRemoteDaemonPendingCallRegistry.swift */; };
 		NRWS00000000000000000008 /* WorkspaceRemoteSSHBatchCommandBuilder.swift in Sources */ = {isa = PBXBuildFile; fileRef = NRWS00000000000000000007 /* WorkspaceRemoteSSHBatchCommandBuilder.swift */; };
 		NRWS00000000000000000010 /* WorkspaceRemoteDaemonRPCClient.swift in Sources */ = {isa = PBXBuildFile; fileRef = NRWS00000000000000000009 /* WorkspaceRemoteDaemonRPCClient.swift */; };
@@ -284,6 +289,11 @@
 		A5001419 /* MarkdownPanelView.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = Panels/MarkdownPanelView.swift; sourceTree = "<group>"; };
 		A5001416 /* Workspace.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = Workspace.swift; sourceTree = "<group>"; };
 		A5FF0002 /* WorkspaceRemoteSession.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = WorkspaceRemoteSession.swift; sourceTree = "<group>"; };
+		NRWS00000000000000000017 /* WorkspaceRemoteSessionController+ConnectionOrchestration.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = "WorkspaceRemoteSessionController+ConnectionOrchestration.swift"; sourceTree = "<group>"; };
+		NRWS00000000000000000019 /* WorkspaceRemoteSessionController+ProcessExecution.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = "WorkspaceRemoteSessionController+ProcessExecution.swift"; sourceTree = "<group>"; };
+		NRWS00000000000000000021 /* WorkspaceRemoteSessionController+DaemonInstall.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = "WorkspaceRemoteSessionController+DaemonInstall.swift"; sourceTree = "<group>"; };
+		NRWS00000000000000000023 /* WorkspaceRemoteSessionController+ScriptBuilders.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = "WorkspaceRemoteSessionController+ScriptBuilders.swift"; sourceTree = "<group>"; };
+		NRWS00000000000000000025 /* WorkspaceRemoteSessionController+PortScanning.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = "WorkspaceRemoteSessionController+PortScanning.swift"; sourceTree = "<group>"; };
 		NRWS00000000000000000005 /* WorkspaceRemoteDaemonPendingCallRegistry.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = WorkspaceRemoteDaemonPendingCallRegistry.swift; sourceTree = "<group>"; };
 		NRWS00000000000000000007 /* WorkspaceRemoteSSHBatchCommandBuilder.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = WorkspaceRemoteSSHBatchCommandBuilder.swift; sourceTree = "<group>"; };
 		NRWS00000000000000000009 /* WorkspaceRemoteDaemonRPCClient.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = WorkspaceRemoteDaemonRPCClient.swift; sourceTree = "<group>"; };
@@ -532,6 +542,11 @@
 					A5001511 /* UITestRecorder.swift */,
 					A5001416 /* Workspace.swift */,
 					A5FF0002 /* WorkspaceRemoteSession.swift */,
+					NRWS00000000000000000017 /* WorkspaceRemoteSessionController+ConnectionOrchestration.swift */,
+					NRWS00000000000000000019 /* WorkspaceRemoteSessionController+ProcessExecution.swift */,
+					NRWS00000000000000000021 /* WorkspaceRemoteSessionController+DaemonInstall.swift */,
+					NRWS00000000000000000023 /* WorkspaceRemoteSessionController+ScriptBuilders.swift */,
+					NRWS00000000000000000025 /* WorkspaceRemoteSessionController+PortScanning.swift */,
 					NRWS00000000000000000005 /* WorkspaceRemoteDaemonPendingCallRegistry.swift */,
 					NRWS00000000000000000007 /* WorkspaceRemoteSSHBatchCommandBuilder.swift */,
 					NRWS00000000000000000009 /* WorkspaceRemoteDaemonRPCClient.swift */,
@@ -869,6 +884,11 @@
 						A5001501 /* UITestRecorder.swift in Sources */,
 						A5001406 /* Workspace.swift in Sources */,
 						A5FF0012 /* WorkspaceRemoteSession.swift in Sources */,
+						NRWS00000000000000000018 /* WorkspaceRemoteSessionController+ConnectionOrchestration.swift in Sources */,
+						NRWS00000000000000000020 /* WorkspaceRemoteSessionController+ProcessExecution.swift in Sources */,
+						NRWS00000000000000000022 /* WorkspaceRemoteSessionController+DaemonInstall.swift in Sources */,
+						NRWS00000000000000000024 /* WorkspaceRemoteSessionController+ScriptBuilders.swift in Sources */,
+						NRWS00000000000000000026 /* WorkspaceRemoteSessionController+PortScanning.swift in Sources */,
 						NRWS00000000000000000006 /* WorkspaceRemoteDaemonPendingCallRegistry.swift in Sources */,
 						NRWS00000000000000000008 /* WorkspaceRemoteSSHBatchCommandBuilder.swift in Sources */,
 						NRWS00000000000000000010 /* WorkspaceRemoteDaemonRPCClient.swift in Sources */,