fix: harden reasoning effort edge cases

.brv/context-tree/architecture/plugin_options/plugin_options_configurability.md

@@ -1,18 +1,18 @@
 ---
 title: Plugin Options Configurability
-summary: AdaptiveThinkingPlugin now supports configurable enabled/quiet flags, service and tool naming, custom tool descriptions and system prompts, with invalid config logging and disabled-plugin no-op behavior.
+summary: Plugin options now support enabled, quiet, toolName, toolDescription, and systemPrompt; serviceName is removed from public config and defaults remain functional.
 tags: []
-related: [facts/project/reasoning_effort_behavior.md, facts/project/reasoning_effort_confirmation.md]
+related: [facts/project/reasoning_effort_behavior.md, facts/project/reasoning_effort_confirmation.md, project_management/pull_requests/pr_6_replacement_for_default_options_changes.md]
 keywords: []
 createdAt: '2026-04-25T12:40:26.166Z'
-updatedAt: '2026-04-25T12:49:59.689Z'
+updatedAt: '2026-04-25T17:44:35.947Z'
 ---
 ## Reason
-Document configurable plugin options and validation behavior for the adaptive thinking plugin
+Capture the plugin configuration surface and defaults.
 
 ## Raw Concept
 **Task:**
-Document the configurable plugin options added to AdaptiveThinkingPlugin.
+Document plugin configuration support and default behavior
 
 **Changes:**
 - Identified that the current plugin behavior is hard-coded in src/index.ts
@@ -27,6 +27,9 @@ Document the configurable plugin options added to AdaptiveThinkingPlugin.
 - Added tests for config behavior
 - Updated README with config docs and example
 - Added a minor changeset
+- Added plugin config support for enabled, quiet, toolName, toolDescription, and systemPrompt
+- Removed serviceName from public config
+- Kept internal log service fixed as opencode-adaptive-thinking
 
 **Files:**
 - src/index.ts
@@ -37,21 +40,21 @@ Document the configurable plugin options added to AdaptiveThinkingPlugin.
 - .changeset/configurable-plugin-options.md
 
 **Flow:**
-load config -> validate with Zod -> if invalid log and toast -> if disabled return {} -> otherwise expose configured tool and guidance
+plugin loads config -> validates with Zod -> applies defaults -> runs with optional overrides
 
 **Timestamp:** 2026-04-25
 
-**Author:** Ian
+**Author:** assistant
 
 ## Narrative
 ### Structure
-The implementation centralizes plugin configuration in src/config.ts and threads the validated options into AdaptiveThinkingPlugin so runtime behavior and exposed tool metadata can be customized.
+Configuration is defined in src/config.ts, consumed by src/index.ts, and documented in README.md. Tests cover disabled plugin behavior, invalid config handling, custom tool metadata, custom system prompt, and default-options regression.
 
 ### Dependencies
-Depends on the existing opencode-byterover config pattern, Zod validation, and the plugin runtime that shows toasts and logs errors on invalid configuration.
+Uses Zod for schema validation and relies on high-signal tests to protect the public config surface.
 
 ### Highlights
-Tests, typecheck, lint, format check, and build all passed after the implementation. Validation only found formatting drift in src/index.test.ts before formatting was applied.
+The config surface is intentionally kept small and does not expose serviceName. Default behavior is treated as a regression requirement.
 
 ### Rules
 Curate only information with lasting value: facts, decisions, technical details, preferences, or notable outcomes.
@@ -60,8 +63,7 @@ Curate only information with lasting value: facts, decisions, technical details,
 Example options include enabled, quiet, serviceName, toolName, toolDescription, and systemPrompt.
 
 ## Facts
-- **config_pattern**: The plugin uses the opencode-byterover config pattern. [project]
-- **plugin_options**: Supported options are enabled, quiet, serviceName, toolName, toolDescription, and systemPrompt. [project]
-- **invalid_config_behavior**: Invalid config logs an error, shows a toast, and returns {}. [project]
-- **disabled_plugin_behavior**: Disabled plugin returns {}. [project]
-- **tool_name_behavior**: Custom toolName updates both the exposed tool and the system prompt guidance. [project]
+- **plugin_options**: The plugin supports configurable enabled, quiet, toolName, toolDescription, and systemPrompt options. [project]
+- **service_name_config**: serviceName was removed from the public config surface. [project]
+- **internal_log_service_name**: The internal log service name remains opencode-adaptive-thinking. [project]
+- **default_options_behavior**: Default plugin behavior must continue working when no options are provided. [project]

.brv/context-tree/facts/preference/reasoning_effort.md

@@ -1,10 +1,10 @@
 ---
-title: Reasoning Effort
+createdAt: '2026-04-25T10:20:14.913Z'
+keywords: []
+related: [facts/project/reasoning_effort_confirmation.md, facts/project/reasoning_effort_reset_message.md, facts/project/reasoning_effort_reset_notice.md, facts/project/reasoning_effort_reset_notice_visibility.md, facts/project/reasoning_effort_reset_behavior.md, facts/project/reasoning_effort_behavior.md, facts/project/reasoning_effort_state_handling.md, facts/project/reasoning_effort_medium_handling.md]
 summary: Reasoning effort preference is set to low.
 tags: []
-related: []
-keywords: []
-createdAt: '2026-04-25T10:20:14.913Z'
+title: Reasoning Effort
 updatedAt: '2026-04-25T11:55:01.662Z'
 ---
 ## Reason

.brv/context-tree/facts/project/bounded_session_state_lru_cache.md

@@ -0,0 +1,48 @@
+---
+createdAt: '2026-04-25T17:44:36.487Z'
+keywords: []
+related: [project_management/pull_requests/pr_6_replacement_for_default_options_changes.md, facts/project/reasoning_effort_state_handling.md, facts/project/reasoning_effort_behavior.md]
+summary: Per-session adaptive-thinking state was replaced with a bounded LRU cache capped at 500 sessions, with regression coverage for eviction and type narrowing fixes.
+tags: []
+title: Bounded Session State LRU Cache
+updatedAt: '2026-04-25T17:44:36.487Z'
+---
+## Reason
+Capture the bounded per-session state change and its test coverage.
+
+## Raw Concept
+**Task:**
+Document bounded session state behavior and related regression coverage
+
+**Changes:**
+- Replaced module-level Maps with bounded LRU-backed session state
+- Added eviction regression test
+- Fixed a typecheck issue by narrowing resolvedVariant before assignment
+
+**Files:**
+- src/index.ts
+- src/index.test.ts
+
+**Flow:**
+session interaction -> resolve variant state -> store in LRU -> evict oldest entry when cap exceeded
+
+**Timestamp:** 2026-04-25
+
+**Author:** assistant
+
+## Narrative
+### Structure
+The plugin previously kept state in three module-level Maps; it now uses a single bounded LRU cache to prevent growth in long-running processes.
+
+### Dependencies
+Requires regression tests to preserve default behavior and eviction semantics while keeping the implementation type-safe.
+
+### Highlights
+The cache is capped at 500 sessions and protects the process from unbounded memory growth.
+
+## Facts
+- **session_state_storage**: Per-session state was replaced with a bounded LRU cache. [project]
+- **session_state_lru_cap**: The LRU cache cap is 500 sessions. [project]
+- **old_session_state_maps**: The old unbounded state used three module-level Maps: currentVariant, persistedVariant, and temporaryResetVariant. [project]
+- **lru_eviction_regression_test**: A regression test verifies that the oldest session state is evicted after cache pressure. [project]
+- **typecheck_fix**: A typecheck issue was fixed by narrowing resolvedVariant before assignment. [project]

.brv/context-tree/facts/project/git_branch_checkout_safety.md

@@ -1,10 +1,10 @@
 ---
-title: Git branch checkout safety
+createdAt: '2026-04-25T12:25:59.254Z'
+keywords: []
+related: [facts/project/git_stash_reapply_outcome.md]
 summary: Use Git refusal as a safety signal; stash conflicting local .brv changes with a clear label before switching branches and pulling updates.
 tags: []
-related: []
-keywords: []
-createdAt: '2026-04-25T12:25:59.254Z'
+title: Git branch checkout safety
 updatedAt: '2026-04-25T12:25:59.254Z'
 ---
 ## Reason

.brv/context-tree/facts/project/git_stash_reapply_outcome.md

@@ -1,10 +1,10 @@
 ---
-title: Git Stash Reapply Outcome
+createdAt: '2026-04-25T12:27:24.819Z'
+keywords: []
+related: [facts/project/git_branch_checkout_safety.md]
 summary: Reapplying stash on main restored .brv context-tree changes without dropping the stash; reasoning-effort state handling and medium handling files were restored, while git branch checkout safety file remained present.
 tags: []
-related: []
-keywords: []
-createdAt: '2026-04-25T12:27:24.819Z'
+title: Git Stash Reapply Outcome
 updatedAt: '2026-04-25T12:27:24.819Z'
 ---
 ## Reason

.brv/context-tree/facts/project/pr_push_outcome.md

@@ -1,10 +1,10 @@
 ---
-title: PR Push Outcome
+createdAt: '2026-04-25T13:12:20.630Z'
+keywords: []
+related: [facts/project/reasoning_effort_medium_handling.md]
 summary: The remaining .brv memory was committed as 7edf357 and pushed; the PR branch is clean and up to date with origin/feat/configurable-plugin-options.
 tags: []
-related: []
-keywords: []
-createdAt: '2026-04-25T13:12:20.630Z'
+title: PR Push Outcome
 updatedAt: '2026-04-25T13:12:20.630Z'
 ---
 ## Reason

.brv/context-tree/facts/project/reasoning_effort_behavior.md

@@ -1,18 +1,18 @@
 ---
 title: Reasoning Effort Behavior
-summary: Temporary low reasoning effort can be set in a live session, invalid levels are rejected, and the next idle transition should reset to medium once.
+summary: Reasoning effort behavior now honors quiet invalid-config handling, ignores stale cached variants for the current model, and resolves the newest relevant agent; README and tests were updated and the suite passed.
 tags: []
-related: []
+related: [facts/preference/reasoning_effort.md, facts/project/reasoning_effort_confirmation.md, facts/project/reasoning_effort_reset_message.md, facts/project/reasoning_effort_reset_notice.md, facts/project/reasoning_effort_reset_notice_visibility.md, facts/project/reasoning_effort_reset_behavior.md, facts/project/reasoning_effort_state_handling.md, facts/project/reasoning_effort_medium_handling.md, facts/project/bounded_session_state_lru_cache.md, project_management/pull_requests/context.md]
 keywords: []
 createdAt: '2026-04-25T11:53:01.433Z'
-updatedAt: '2026-04-25T11:54:28.539Z'
+updatedAt: '2026-04-26T10:57:08.718Z'
 ---
 ## Reason
-Persist lasting knowledge about reasoning effort behavior, validation, and checks
+Capture durable implementation and verification details from the conversation
 
 ## Raw Concept
 **Task:**
-Document reasoning effort session behavior and verification outcomes
+Document the reasoning effort behavior changes and verification outcomes
 
 **Changes:**
 - Split state into currentVariant, persistedVariant, and temporaryResetVariant
@@ -27,36 +27,52 @@ Document reasoning effort session behavior and verification outcomes
 - Confirmed invalid reasoning effort level is rejected before mutation
 - Observed expected one-time idle reset behavior to medium
 - Verified tests, typecheck, lint, format:check, and build passed
+- Identified quiet mode bug where invalid config still shows a toast.
+- Noted build bundling is large and should externalize runtime dependencies.
+- Observed cached variants should be validated against current model variants.
+- Flagged fallback agent resolution overwriting agentName when scanning messages backward.
+- Highlighted inconsistent error serialization across code paths.
+- Outlined missing edge-case tests and README usability gaps.
+- Considered configurable reset behavior for temporary effort handling.
+- Called out module-level singleton state as a potential multi-instance risk.
+- Honors quiet: true for invalid config
+- Ignores stale cached reasoning effort for the current model
+- Resolves fallback agent using the newest relevant agent
+- Expanded regression tests and README documentation
 
 **Files:**
 - src/index.ts
 - src/index.test.ts
+- README.md
 
 **Flow:**
-set reasoning effort -> validate level -> run checks -> idle transition resets to medium once
+add regression tests -> confirm failures -> apply minimal fixes -> expand README -> run verification suite
 
-**Timestamp:** 2026-04-25T11:54:23.547Z
+**Timestamp:** 2026-04-26T10:57:02.697Z
 
 **Author:** assistant
 
 ## Narrative
 ### Structure
-This entry records a live-session reasoning-effort state change and the expected follow-up idle reset behavior.
+The update spans production logic in src/index.ts, coverage in src/index.test.ts, and user-facing documentation in README.md.
 
 ### Dependencies
-The behavior depends on the session state machine and validation for allowed reasoning effort levels.
+The behavior depends on current model validity, cached reasoning state, and agent resolution order.
 
 ### Highlights
-A temporary low setting was accepted, an invalid level was rejected, and the next idle transition should restore medium only once.
+The work completed successfully after tests turned green, and the verification suite passed in full.
 
 ### Rules
 Temporary reasoning effort now resets only once on session.idle. Reset prompts are ignored and should not remain visible in-context. Invalid levels are rejected before calling promptAsync or mutating state.
 
 ### Examples
-Checks that passed included pnpm run test, pnpm run typecheck, pnpm run lint, pnpm run format:check, and pnpm run build.
+Examples mentioned include quiet invalid-config handling, stale cache invalidation, and newest-agent fallback resolution.
 
 ## Facts
-- **reasoning_effort**: Reasoning effort was set to low in a live session. [project]
-- **reasoning_effort_validation**: Invalid reasoning effort levels are rejected before mutation. [project]
-- **reasoning_effort_reset_behavior**: The temporary low reasoning effort should reset to medium once on idle, then stop repeating. [project]
-- **verification_status**: Automated checks passed: test, typecheck, lint, format:check, and build. [project]
+- **reasoning_effort**: Reasoning effort was set to high [project]
+- **quiet_invalid_config_behavior**: The implementation now honors quiet: true for invalid config to suppress toast while still logging [project]
+- **stale_cached_variants**: Cached reasoning effort is ignored when it is invalid for the current model [project]
+- **agent_fallback_resolution**: Fallback agent resolution uses the newest relevant agent [project]
+- **test_coverage**: Regression tests were added for quiet config errors, stale cached variants, newest-agent fallback, provider lookup failure, and reset failure recovery [project]
+- **verification_suite**: The project verification suite passed: format:check, lint, typecheck, test, and build [project]
+- **test_results**: The test suite reported 15 passed [project]

.brv/context-tree/facts/project/reasoning_effort_confirmation.md

@@ -1,10 +1,10 @@
 ---
-title: Reasoning Effort Confirmation
+createdAt: '2026-04-25T11:06:39.753Z'
+keywords: []
+related: [facts/preference/reasoning_effort.md, facts/project/reasoning_effort_reset_message.md, facts/project/reasoning_effort_reset_notice.md, facts/project/reasoning_effort_reset_notice_visibility.md, facts/project/reasoning_effort_reset_behavior.md, facts/project/reasoning_effort_behavior.md, facts/project/reasoning_effort_state_handling.md, facts/project/reasoning_effort_medium_handling.md]
 summary: The only visible confirmation after the tool call was "Reasoning effort set to low".
 tags: []
-related: []
-keywords: []
-createdAt: '2026-04-25T11:06:39.753Z'
+title: Reasoning Effort Confirmation
 updatedAt: '2026-04-25T11:08:43.379Z'
 ---
 ## Reason

.brv/context-tree/facts/project/reasoning_effort_medium_handling.md

@@ -1,10 +1,10 @@
 ---
-title: Reasoning Effort Medium Handling
+createdAt: '2026-04-25T11:56:05.207Z'
+keywords: []
+related: [facts/preference/reasoning_effort.md, facts/project/reasoning_effort_confirmation.md, facts/project/reasoning_effort_reset_message.md, facts/project/reasoning_effort_reset_notice.md, facts/project/reasoning_effort_reset_notice_visibility.md, facts/project/reasoning_effort_reset_behavior.md, facts/project/reasoning_effort_behavior.md, facts/project/reasoning_effort_state_handling.md, facts/project/pr_push_outcome.md]
 summary: Reasoning effort was set to medium, a patch changeset was added for opencode-adaptive-thinking, and formatting, lint, test, and typecheck all passed before committing and pushing only the changeset.
 tags: []
-related: []
-keywords: []
-createdAt: '2026-04-25T11:56:05.207Z'
+title: Reasoning Effort Medium Handling
 updatedAt: '2026-04-25T12:17:35.362Z'
 ---
 ## Reason

.brv/context-tree/facts/project/reasoning_effort_reset_behavior.md

@@ -1,10 +1,10 @@
 ---
-title: Reasoning Effort Reset Behavior
+createdAt: '2026-04-25T11:09:11.082Z'
+keywords: []
+related: [facts/preference/reasoning_effort.md, facts/project/reasoning_effort_confirmation.md, facts/project/reasoning_effort_reset_message.md, facts/project/reasoning_effort_reset_notice.md, facts/project/reasoning_effort_reset_notice_visibility.md, facts/project/reasoning_effort_behavior.md, facts/project/reasoning_effort_state_handling.md, facts/project/reasoning_effort_medium_handling.md]
 summary: Reasoning effort can be reset to medium, and the reset notice states that it has been reset to medium.
 tags: []
-related: []
-keywords: []
-createdAt: '2026-04-25T11:09:11.082Z'
+title: Reasoning Effort Reset Behavior
 updatedAt: '2026-04-25T11:54:47.414Z'
 ---
 ## Reason

.brv/context-tree/facts/project/reasoning_effort_reset_message.md

@@ -1,10 +1,10 @@
 ---
-title: Reasoning Effort Reset Message
+createdAt: '2026-04-25T11:08:33.219Z'
+keywords: []
+related: [facts/preference/reasoning_effort.md, facts/project/reasoning_effort_confirmation.md, facts/project/reasoning_effort_reset_notice.md, facts/project/reasoning_effort_reset_notice_visibility.md, facts/project/reasoning_effort_reset_behavior.md, facts/project/reasoning_effort_behavior.md, facts/project/reasoning_effort_state_handling.md, facts/project/reasoning_effort_medium_handling.md]
 summary: Reasoning effort was reset to medium, with no separate tool-generated reset confirmation observed beyond an earlier low setting message.
 tags: []
-related: []
-keywords: []
-createdAt: '2026-04-25T11:08:33.219Z'
+title: Reasoning Effort Reset Message
 updatedAt: '2026-04-25T11:11:38.940Z'
 ---
 ## Reason

.brv/context-tree/facts/project/reasoning_effort_reset_notice.md

@@ -1,10 +1,10 @@
 ---
-title: Reasoning Effort Reset Notice
+createdAt: '2026-04-25T11:44:48.223Z'
+keywords: []
+related: [facts/preference/reasoning_effort.md, facts/project/reasoning_effort_confirmation.md, facts/project/reasoning_effort_reset_message.md, facts/project/reasoning_effort_reset_notice_visibility.md, facts/project/reasoning_effort_reset_behavior.md, facts/project/reasoning_effort_behavior.md, facts/project/reasoning_effort_state_handling.md, facts/project/reasoning_effort_medium_handling.md]
 summary: Reasoning effort reset notice is visible and states that reasoning effort reset to medium.
 tags: []
-related: []
-keywords: []
-createdAt: '2026-04-25T11:44:48.223Z'
+title: Reasoning Effort Reset Notice
 updatedAt: '2026-04-25T11:44:48.223Z'
 ---
 ## Reason

.brv/context-tree/facts/project/reasoning_effort_reset_notice_visibility.md

@@ -1,10 +1,10 @@
 ---
-title: Reasoning Effort Reset Notice Visibility
+createdAt: '2026-04-25T11:12:05.181Z'
+keywords: []
+related: [facts/preference/reasoning_effort.md, facts/project/reasoning_effort_confirmation.md, facts/project/reasoning_effort_reset_message.md, facts/project/reasoning_effort_reset_notice.md, facts/project/reasoning_effort_reset_behavior.md, facts/project/reasoning_effort_behavior.md, facts/project/reasoning_effort_state_handling.md, facts/project/reasoning_effort_medium_handling.md]
 summary: The reset notice is visible as a user-level message rather than a separate tool confirmation.
 tags: []
-related: []
-keywords: []
-createdAt: '2026-04-25T11:12:05.181Z'
+title: Reasoning Effort Reset Notice Visibility
 updatedAt: '2026-04-25T11:12:05.181Z'
 ---
 ## Reason

.brv/context-tree/facts/project/reasoning_effort_state_handling.md

@@ -1,10 +1,10 @@
 ---
-title: Reasoning Effort State Handling
+createdAt: '2026-04-25T11:48:50.291Z'
+keywords: []
+related: [facts/preference/reasoning_effort.md, facts/project/reasoning_effort_confirmation.md, facts/project/reasoning_effort_reset_message.md, facts/project/reasoning_effort_reset_notice.md, facts/project/reasoning_effort_reset_notice_visibility.md, facts/project/reasoning_effort_reset_behavior.md, facts/project/reasoning_effort_behavior.md, facts/project/reasoning_effort_medium_handling.md, facts/project/bounded_session_state_lru_cache.md]
 summary: SDK types were restored in src/index.ts, the PR title was changed to conventional commit style, and verification passed.
 tags: []
-related: []
-keywords: []
-createdAt: '2026-04-25T11:48:50.291Z'
+title: Reasoning Effort State Handling
 updatedAt: '2026-04-25T12:13:21.426Z'
 ---
 ## Reason