feat(delegation): uncap max_spawn_depth (floor 1, no ceiling) (#39772)

* fix: respect disabled auto-compaction on context overflow

Port from anomalyco/opencode#30749.

When compression.enabled is false, NO automatic compaction trigger may
fire. The proactive token-threshold paths (preflight + post-response
should_compress gate) already honoured the setting, but the three
provider-overflow recovery paths in the agent loop — long-context-tier
429, 413 payload-too-large, and context-overflow — called
_compress_context() unconditionally, silently compressing and rotating
the session against the user's explicit choice.

Add a single guard at the top of the overflow-recovery dispatch: when
compression is disabled and the error is one of those three overflow
classes, surface a terminal error (compaction_disabled: True) telling the
user to /compress manually, /new, switch to a larger-context model, or
reduce attachments. Manual /compress (force=True) is unaffected — it never
enters this loop.

Tests: new TestOverflowWithCompactionDisabled (413 + 400 overflow don't
compress when disabled; control case still compresses when enabled).
Existing overflow-recovery tests updated to enable compaction explicitly
(they verify the recovery fires); fixture defaults flipped to True to
match production (compression.enabled defaults to True).

* feat(delegation): uncap max_spawn_depth to match max_concurrent_children

Removed the hard ceiling of 3 on delegation.max_spawn_depth. Depth now has
a floor of 1 and no upper limit, mirroring max_concurrent_children. Cost
(each level multiplies API spend) is the practical limiter, not a constant.

- delegate_tool.py: drop _MAX_SPAWN_DEPTH_CAP, _get_max_spawn_depth() floors
  at 1 instead of clamping to [1,3]; depth-limit error string reworded
- config.py / cli-config.yaml.example: doc comments say floor 1, no ceiling
- docs (configuration, delegation, delegation-patterns): range 1-3 -> >=1
- tests: convert clamp-above-3 change-detector into a no-ceiling invariant,
  drop the _MAX_SPAWN_DEPTH_CAP==3 snapshot assert, fix warning-text assert

website/docs/guides/delegation-patterns.md

@@ -218,14 +218,14 @@ Restricting toolsets keeps the subagent focused and prevents accidental side eff
 ## Constraints
 
 - **Default 3 parallel tasks**: batches default to 3 concurrent subagents (configurable via `delegation.max_concurrent_children` in config.yaml, no hard ceiling, only a floor of 1)
-- **Nested delegation is opt-in**: leaf subagents (default) cannot call `delegate_task`, `clarify`, `memory`, `send_message`, or `execute_code`. Orchestrator subagents (`role="orchestrator"`) retain `delegate_task` for further delegation, but only when `delegation.max_spawn_depth` is raised above the default of 1 (1-3 supported); the other four remain blocked. Disable globally via `delegation.orchestrator_enabled: false`.
+- **Nested delegation is opt-in**: leaf subagents (default) cannot call `delegate_task`, `clarify`, `memory`, `send_message`, or `execute_code`. Orchestrator subagents (`role="orchestrator"`) retain `delegate_task` for further delegation, but only when `delegation.max_spawn_depth` is raised above the default of 1 (floor 1, no ceiling); the other four remain blocked. Disable globally via `delegation.orchestrator_enabled: false`.
 
 ### Tuning Concurrency and Depth
 
 | Config | Default | Range | Effect |
 |--------|---------|-------|--------|
 | `max_concurrent_children` | 3 | >=1 | Parallel batch size per `delegate_task` call |
-| `max_spawn_depth` | 1 | 1-3 | How many delegation levels can spawn further |
+| `max_spawn_depth` | 1 | >=1 | How many delegation levels can spawn further |
 
 Example: running 30 parallel workers with nested subagents:
 

website/docs/user-guide/configuration.md

@@ -1672,7 +1672,7 @@ delegation:
   # api_key: "local-key"                    # API key for base_url (falls back to OPENAI_API_KEY)
   # api_mode: ""                            # Wire protocol for base_url: "chat_completions", "codex_responses", or "anthropic_messages". Empty = auto-detect from URL (e.g. /anthropic suffix → anthropic_messages). Set explicitly for non-standard endpoints the heuristic can't detect.
   max_concurrent_children: 3                # Parallel children per batch (floor 1, no ceiling). Also via DELEGATION_MAX_CONCURRENT_CHILDREN env var.
-  max_spawn_depth: 1                        # Delegation tree depth cap (1-3, clamped). 1 = flat (default): parent spawns leaves that cannot delegate. 2 = orchestrator children can spawn leaf grandchildren. 3 = three levels.
+  max_spawn_depth: 1                        # Delegation tree depth (floor 1, no ceiling). 1 = flat (default): parent spawns leaves that cannot delegate. 2 = orchestrator children can spawn leaf grandchildren. 3+ = deeper trees.
   orchestrator_enabled: true                # Global kill switch. When false, role="orchestrator" is ignored and every child is forced to leaf regardless of max_spawn_depth.
 ```
 
@@ -1686,7 +1686,7 @@ The delegation provider uses the same credential resolution as CLI/gateway start
 
 **Precedence:** `delegation.base_url` in config → `delegation.provider` in config → parent provider (inherited). `delegation.model` in config → parent model (inherited). Setting just `model` without `provider` changes only the model name while keeping the parent's credentials (useful for switching models within the same provider like OpenRouter).
 
-**Width and depth:** `max_concurrent_children` caps how many subagents run in parallel per batch (default `3`, floor of 1, no ceiling). Can also be set via the `DELEGATION_MAX_CONCURRENT_CHILDREN` env var. When the model submits a `tasks` array longer than the cap, `delegate_task` returns a tool error explaining the limit rather than silently truncating. `max_spawn_depth` controls the delegation tree depth (clamped to 1-3). At the default `1`, delegation is flat: children cannot spawn grandchildren, and passing `role="orchestrator"` silently degrades to `leaf`. Raise to `2` so orchestrator children can spawn leaf grandchildren; `3` for three-level trees. The agent opts into orchestration per call via `role="orchestrator"`; `orchestrator_enabled: false` forces every child back to leaf regardless. Cost scales multiplicatively — at `max_spawn_depth: 3` with `max_concurrent_children: 3`, the tree can reach 3×3×3 = 27 concurrent leaf agents. See [Subagent Delegation → Depth Limit and Nested Orchestration](features/delegation.md#depth-limit-and-nested-orchestration) for usage patterns.
+**Width and depth:** `max_concurrent_children` caps how many subagents run in parallel per batch (default `3`, floor of 1, no ceiling). Can also be set via the `DELEGATION_MAX_CONCURRENT_CHILDREN` env var. When the model submits a `tasks` array longer than the cap, `delegate_task` returns a tool error explaining the limit rather than silently truncating. `max_spawn_depth` controls the delegation tree depth (floor of 1, no upper ceiling). At the default `1`, delegation is flat: children cannot spawn grandchildren, and passing `role="orchestrator"` silently degrades to `leaf`. Raise to `2` so orchestrator children can spawn leaf grandchildren; `3` for three-level trees, and higher for deeper ones. The agent opts into orchestration per call via `role="orchestrator"`; `orchestrator_enabled: false` forces every child back to leaf regardless. Cost scales multiplicatively — at `max_spawn_depth: 3` with `max_concurrent_children: 3`, the tree can reach 3×3×3 = 27 concurrent leaf agents. See [Subagent Delegation → Depth Limit and Nested Orchestration](features/delegation.md#depth-limit-and-nested-orchestration) for usage patterns.
 
 ## Clarify
 

website/docs/user-guide/features/delegation.md

@@ -214,7 +214,7 @@ delegate_task(
 ```
 
 - `role="leaf"` (default): child cannot delegate further — identical to the flat-delegation behavior.
-- `role="orchestrator"`: child retains the `delegation` toolset. Gated by `delegation.max_spawn_depth` (default **1** = flat, so `role="orchestrator"` is a no-op at defaults). Raise `max_spawn_depth` to 2 to allow orchestrator children to spawn leaf grandchildren; 3 for three levels (cap).
+- `role="orchestrator"`: child retains the `delegation` toolset. Gated by `delegation.max_spawn_depth` (default **1** = flat, so `role="orchestrator"` is a no-op at defaults). Raise `max_spawn_depth` to 2 to allow orchestrator children to spawn leaf grandchildren; 3+ for deeper trees. There is no upper ceiling — cost is the practical limit.
 - `delegation.orchestrator_enabled: false`: global kill switch that forces every child to `leaf` regardless of the `role` parameter.
 
 **Cost warning:** With `max_spawn_depth: 3` and `max_concurrent_children: 3`, the tree can reach 3×3×3 = 27 concurrent leaf agents. Each extra level multiplies spend — raise `max_spawn_depth` intentionally.
@@ -264,7 +264,7 @@ For **durable long-running work** that must survive interrupts or outlive the cu
 delegation:
   max_iterations: 50                        # Max turns per child (default: 50)
   # max_concurrent_children: 3              # Parallel children per batch (default: 3)
-  # max_spawn_depth: 1                      # Tree depth (1-3, default 1 = flat). Raise to 2 to allow orchestrator children to spawn leaves; 3 for three levels.
+  # max_spawn_depth: 1                      # Tree depth (floor 1, no ceiling, default 1 = flat). Raise to 2 to allow orchestrator children to spawn leaves; 3+ for deeper trees.
   # orchestrator_enabled: true              # Disable to force all children to leaf role.
   model: "google/gemini-3-flash-preview"             # Optional provider/model override
   provider: "openrouter"                             # Optional built-in provider