Add per-agent reasoning effort

Opus 4.5+ and Sonnet 4.6+ support a new "effort" knob that controls how
much budget the model spends on thinking and tool calls. Plumb it through
end to end so each agent can pick its own level.

Storage & shape:
- New TEXT column agents.effort (default '') added via TryAddColumn.
- AgentRecord.Effort + INSERT/UPDATE in DatabaseService.Agents.cs.
- ChatContext.Effort + SubAgentContext.Effort so the value travels with the
  request alongside model and tool settings.

Agent editor:
- Effort dropdown above git-commit behavior in the agent form (low/medium/
  high/xhigh/max plus empty = "use default"). Always visible; on OpenAI
  providers the value is sent but silently ignored.
- agent-page.js load/save and AgentEndpoint create/update wired up.

Anthropic API path:
- StreamChat and RunNonStreamingToolLoop add output_config: { effort } when
  effort is set and not "high" – empty/null/"high" means "omit and let the
  API pick its default".
- Sub-agents (preparer/review/finalizer) get the parameter through
  RunAgentChat so each step uses its own agent's effort.

Anthropic CLI path:
- ClaudeCliService.ChatStreamingAsync takes an effort parameter and exports
  CLAUDE_CODE_EFFORT_LEVEL on the spawned process. Env-var beats the
  --effort flag because it also covers "max" and "ultracode".
- StreamChatViaCli, ChatNonStreamingViaCli, RunSubAgentViaCli, and the
  ChatEndpoint anthropic branches all hand the value through.

ARCHITECTURE.md / ARCHITECTURE_QUICK.md updated with the new field.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

Endpoints/AgentEndpoint.cs

@@ -71,6 +71,7 @@ public static class AgentEndpoint
                 a.WebSearchVersion,
                 a.AllowUserChoice,
                 a.TaskInstruction,
+                a.Effort,
                 a.AvatarScale,
                 a.AvatarOffsetX,
                 a.AvatarOffsetY,
@@ -137,6 +138,7 @@ public static class AgentEndpoint
             WebSearchVersion = body.TryGetProperty("webSearchVersion", out var wsv2) ? wsv2.GetString() ?? "" : "",
             AllowUserChoice = !body.TryGetProperty("allowUserChoice", out var auc) || auc.GetBoolean(),
             TaskInstruction = body.TryGetProperty("taskInstruction", out var ti) ? ti.GetString() : null,
+            Effort = body.TryGetProperty("effort", out var ef) ? ef.GetString() ?? "" : "",
             AvatarScale = body.TryGetProperty("avatarScale", out var asc) ? asc.GetDouble() : 1.0,
             AvatarOffsetX = body.TryGetProperty("avatarOffsetX", out var aox) ? aox.GetDouble() : 0,
             AvatarOffsetY = body.TryGetProperty("avatarOffsetY", out var aoy) ? aoy.GetDouble() : 0,
@@ -184,6 +186,7 @@ public static class AgentEndpoint
         }
         if (body.TryGetProperty("allowUserChoice", out var auc)) agent.AllowUserChoice = auc.GetBoolean();
         if (body.TryGetProperty("taskInstruction", out var ti)) agent.TaskInstruction = ti.GetString();
+        if (body.TryGetProperty("effort", out var ef)) agent.Effort = ef.GetString() ?? "";
         if (body.TryGetProperty("avatarScale", out var asc)) agent.AvatarScale = asc.GetDouble();
         if (body.TryGetProperty("avatarOffsetX", out var aox)) agent.AvatarOffsetX = aox.GetDouble();
         if (body.TryGetProperty("avatarOffsetY", out var aoy)) agent.AvatarOffsetY = aoy.GetDouble();

Endpoints/ChatEndpoint.cs

@@ -261,7 +261,7 @@ public static class ChatEndpoint
 
                     if (anthropic.IsCliAvailable)
                     {
-                        await anthropic.StreamChatViaCli(res, ctx.ModelId, ctx.SystemPrompt, messages, ctx.ChainId, workspace: ctx.Workspace, allowUserChoice: ctx.Agent?.AllowUserChoice ?? true, planMode: body.PlanMode, webSearch: !string.IsNullOrEmpty(ctx.WebSearchVersion), sessionId: sessionId, agentId: ctx.AgentId, remoteMgr: remoteMgr, unityMcpUrl: ctx.Session?.UnityMcpUrl, unityMcpToken: ctx.Session?.UnityMcpToken, useAutoContext: ctx.Agent?.UseAutoContext ?? true, workCt: workCt, sseCt: sseCt);
+                        await anthropic.StreamChatViaCli(res, ctx.ModelId, ctx.SystemPrompt, messages, ctx.ChainId, workspace: ctx.Workspace, allowUserChoice: ctx.Agent?.AllowUserChoice ?? true, planMode: body.PlanMode, webSearch: !string.IsNullOrEmpty(ctx.WebSearchVersion), sessionId: sessionId, agentId: ctx.AgentId, remoteMgr: remoteMgr, unityMcpUrl: ctx.Session?.UnityMcpUrl, unityMcpToken: ctx.Session?.UnityMcpToken, useAutoContext: ctx.Agent?.UseAutoContext ?? true, effort: ctx.Effort, workCt: workCt, sseCt: sseCt);
                     }
                     else
                     {
@@ -271,7 +271,7 @@ public static class ChatEndpoint
                     return;
                 }
 
-                await anthropic.StreamChat(res, ctx.ModelId, ctx.SystemPrompt, messages, ctx.ChainId, ctx.Workspace, apiToken: anthropicToken, sessionId: sessionId, agentId: ctx.AgentId, userId: userId, useMemory: ctx.UseMemory, webSearchVersion: ctx.WebSearchVersion, maxIterations: ctx.MaxIterations, toolChoice: effectiveToolChoice, review: ctx.Review, finalizer: ctx.Finalizer, allowUserChoice: ctx.Agent?.AllowUserChoice ?? true, planMode: ctx.PlanMode, useAutoContext: ctx.Agent?.UseAutoContext ?? true, useGitHubSearch: ctx.Agent?.UseGitHubSearch ?? false, useSerperSearch: ctx.Agent?.UseSerperSearch ?? false, workCt: workCt, hardCt: hardCt, sseCt: sseCt, remoteMgr: remoteMgr);
+                await anthropic.StreamChat(res, ctx.ModelId, ctx.SystemPrompt, messages, ctx.ChainId, ctx.Workspace, apiToken: anthropicToken, sessionId: sessionId, agentId: ctx.AgentId, userId: userId, useMemory: ctx.UseMemory, webSearchVersion: ctx.WebSearchVersion, maxIterations: ctx.MaxIterations, toolChoice: effectiveToolChoice, review: ctx.Review, finalizer: ctx.Finalizer, allowUserChoice: ctx.Agent?.AllowUserChoice ?? true, planMode: ctx.PlanMode, useAutoContext: ctx.Agent?.UseAutoContext ?? true, useGitHubSearch: ctx.Agent?.UseGitHubSearch ?? false, useSerperSearch: ctx.Agent?.UseSerperSearch ?? false, effort: ctx.Effort, workCt: workCt, hardCt: hardCt, sseCt: sseCt, remoteMgr: remoteMgr);
             }
         }
         finally