feat: inject effort as soft default via CLI flags instead of env var (#104)

CLAUDE_CODE_EFFORT_LEVEL hard-locks effort for the whole session and makes
Claude reject in-session /effort switching (incl. ultracode). Carry effort
as a dedicated payload field instead, injected at spawn as a soft default:

- regular levels (incl. max) -> claude --effort <level>
  (the settings effortLevel key is enum([low,medium,high,xhigh]) with
  .catch(undefined), so max would be silently dropped there)
- ultracode -> claude --settings '{"ultracode":true}'
  (dedicated boolean settings key, rejected by the --effort flag)

Changes:
- add effort enum field to create/quick-start/ralph-loop schemas and thread
  it through Session -> CreateSessionOptions/RespawnPaneOptions -> spawn
- buildEffortCliArgs() in session-cli-builder, shared by tmux spawn command
  and direct-PTY fallback args
- frontend: buildEnvOverrides() no longer emits CLAUDE_CODE_EFFORT_LEVEL;
  validated effort goes into payloads via getEffortSetting()
- settings UI: add Ultracode option to the Thinking Effort dropdown
- legacy migration: Session constructor extracts CLAUDE_CODE_EFFORT_LEVEL
  from persisted envOverrides; applyEnvOverrides() unsets the stale tmux
  session var so respawned panes are no longer locked
- tests: test/effort-injection.test.ts (13 cases)

Co-authored-by: Teigen <teigenzhang@gmail.com>

src/session-cli-builder.ts

@@ -8,7 +8,8 @@
  * @module session-cli-builder
  */
 
-import type { ClaudeMode } from './types.js';
+import type { ClaudeMode, EffortLevel } from './types.js';
+import { isEffortLevel } from './types.js';
 import { getAugmentedPath } from './utils/index.js';
 
 /**
@@ -31,6 +32,23 @@ function buildPermissionArgs(claudeMode: ClaudeMode, allowedTools?: string): str
   }
 }
 
+/**
+ * Build the CLI args carrying the effort level as a SOFT default (switchable
+ * in-session via /effort). The CLAUDE_CODE_EFFORT_LEVEL env var is deliberately
+ * avoided — it hard-locks effort and blocks in-session `/effort` switching.
+ *
+ * Two carriers are needed because neither covers all levels:
+ * - regular levels (incl. `max`) → `--effort <level>` (the settings `effortLevel`
+ *   key is enum(["low","medium","high","xhigh"]) with .catch(undefined), so `max`
+ *   would be SILENTLY dropped there)
+ * - `ultracode` → `--settings '{"ultracode":true}'` (its own boolean settings key,
+ *   claude >= 2.1.154; rejected by the --effort flag)
+ */
+export function buildEffortCliArgs(effort?: EffortLevel): string[] {
+  if (!effort || !isEffortLevel(effort)) return [];
+  return effort === 'ultracode' ? ['--settings', '{"ultracode":true}'] : ['--effort', effort];
+}
+
 /**
  * Build args for an interactive Claude CLI session (direct PTY, non-mux fallback).
  *
@@ -38,16 +56,19 @@ function buildPermissionArgs(claudeMode: ClaudeMode, allowedTools?: string): str
  * @param claudeMode - Permission mode for the CLI
  * @param model - Optional model override (e.g., 'opus', 'sonnet')
  * @param allowedTools - Optional comma-separated allowed tools list
+ * @param effort - Optional effort level, injected via --settings (overridable in-session)
  * @returns Array of CLI arguments
  */
 export function buildInteractiveArgs(
   sessionId: string,
   claudeMode: ClaudeMode,
   model?: string,
-  allowedTools?: string
+  allowedTools?: string,
+  effort?: EffortLevel
 ): string[] {
   const args = [...buildPermissionArgs(claudeMode, allowedTools), '--session-id', sessionId];
   if (model) args.push('--model', model);
+  args.push(...buildEffortCliArgs(effort));
   return args;
 }