Phase 003: remove the coding-agent and ekko-agent runtimes

Every chat session now runs through the Hermes bridge, so the three chat
chains become feature-equivalent instead of three partially-maintained
dispatch paths. Keeping the coding-agent and in-house agent runtimes alive
meant every bridge change had to be mirrored into two more runtimes that
had already drifted.

Historical rows are read, not migrated: sessions stored with the retired
source normalize to cli on load, workflow graphs naming the retired agents
keep loading and run on the bridge, and the visible-source check plus
SOURCE_LABELS still recognize the old value so those sessions stay listed.

The public surface follows the code: the OpenAPI generator and the MCP
chat-run tool schema drop the six retired entry fields so external callers
are not told about runtimes that no longer exist.

harness-check gains a RETIRED_RUNTIME scan so the residual check is a
mechanical gate instead of a manual grep, with the two surviving read-side
compat sites recorded with reasons.

Refs: docs/phases/phase_003.md

packages/client/src/i18n/locales/en.ts

@@ -220,7 +220,6 @@ export default {
     groupMonitoringShort: 'Mon',
     groupTools: 'Tools',
     groupToolsShort: "Tools",
-    codingAgents: "Coding Agents",
     versionPreview: "Version Preview",
     settings: 'Settings',
     connected: 'Connected',
@@ -2069,86 +2068,6 @@ export default {
     stopSuccess: "Preview stopped",
   },
 
-  codingAgents: {
-    title: "Coding Agents",
-    notice: "Not all providers and models are compatible.",
-    claudeDescription: "Anthropic CLI for one-shot print mode and interactive coding sessions.",
-    codexDescription: "OpenAI CLI and Hermes openai-codex provider flow for repository tasks.",
-    copyCommand: "Copy",
-    commandCopied: "Command copied",
-    commandCopyFailed: "Copy failed",
-    refresh: "Refresh",
-    checking: "Checking",
-    installStatus: "Install status",
-    installed: "Installed",
-    notInstalled: "Not installed",
-    installRequired: "{agent} is not installed. Install it before creating a session.",
-    installNow: "Install",
-    installing: "Installing",
-    installSuccess: "Installed",
-    installFailed: "Install failed",
-    installFailedHermesHint: "Installation failed. Ask Hermes to install it for you.",
-    installFailureReason: "Reason",
-    nodeEnvironmentMissing: "Node/npm was not detected. Please install Node.js and try again.",
-    deleteNow: "Delete",
-    deleting: "Deleting",
-    deleteSuccess: "Deleted",
-    deleteFailed: "Delete failed",
-    configFiles: "Config files",
-    profileScope: "Profile",
-    providerScope: "Provider",
-    providerPlaceholder: "e.g. custom:glm",
-    modelScope: "Model",
-    modelPlaceholder: "Select model",
-    launchModeScope: "Launch mode",
-    launchModeGlobal: "Global config",
-    launchModeScoped: "Provider and model",
-    protocolScope: "Protocol",
-    protocolOpenAiChat: "OpenAI Chat Completions (/v1/chat/completions)",
-    protocolOpenAiResponses: "OpenAI Responses (/v1/responses)",
-    protocolAnthropicMessages: "Anthropic Messages (/v1/messages)",
-    reloadConfig: "Reload config",
-    configFileNotCreated: "Not created",
-    configLoadFailed: "Failed to read config file",
-    loadFailed: "Failed to inspect coding agents",
-    launch: "Launch",
-    launchTitle: "Launch Coding Agent",
-    nativeTerminal: "Native Terminal",
-    builtInTerminal: "Built-in Terminal",
-    launchPrepared: "Launch config prepared",
-    launchPrepareFailed: "Failed to prepare launch config",
-    nativeLaunchStarted: "Native terminal opened",
-    nativeLaunchFailed: "Failed to open native terminal",
-    terminalTitle: "Coding Agent Terminal",
-    loadProvidersFailed: "Failed to load providers for the current profile",
-    selectProviderModel: "Select a provider and model",
-    launchConfigDir: "Launch config directory",
-    launchCommand: "Launch command",
-    table: {
-      tool: "Tool",
-      kind: "Step",
-      command: "Command",
-      note: "Note",
-      action: "Action",
-    },
-    kinds: {
-      install: "Install",
-      auth: "Auth",
-      health: "Health",
-      run: "Run",
-    },
-    notes: {
-      claudeInstall: "Installs the Claude Code CLI globally.",
-      codexInstall: "Installs the Codex CLI globally.",
-      claudeAuth: "Checks Claude Code login state; run claude once if login is missing.",
-      codexAuth: "Adds Hermes-managed OpenAI Codex OAuth credentials.",
-      claudeHealth: "Checks updater and local CLI health.",
-      codexHealth: "Confirms the Codex CLI is available on PATH.",
-      claudeRun: "Print mode is the cleanest path for API-driven one-shot tasks.",
-      codexRun: "Codex one-shot tasks must run inside a git repository.",
-    },
-  },
-
   // Platform channel settings
   platform: {
     requireMention: "Require {'@'}Mention",
@@ -2326,7 +2245,7 @@ export default {
     cacheHitRate: 'Cache Hit Rate',
     modelBreakdown: 'Model Breakdown',
     agentBreakdown: 'Agent Breakdown',
-    agents: { hermes: 'Hermes Agent', claudeCode: 'Claude Code', codex: 'Codex', ekkoAgent: 'Ekko Agent', unknown: 'Unknown' },
+    agents: { hermes: 'Hermes Agent', unknown: 'Unknown' },
     dailyTrend: 'Daily Usage',
     date: 'Date',
     tokens: 'Tokens',