diff --git a/src/cli/doctor/checks/dependencies.ts b/src/cli/doctor/checks/dependencies.ts
index 7e273c96b..42876c4a3 100644
--- a/src/cli/doctor/checks/dependencies.ts
+++ b/src/cli/doctor/checks/dependencies.ts
@@ -6,7 +6,11 @@ import type { DependencyInfo } from "../types"
 import { spawnWithTimeout } from "../spawn-with-timeout"
 import { getCachedBinaryPath } from "../../../hooks/comment-checker/downloader"
 
-async function checkBinaryExists(binary: string): Promise<{ exists: boolean; path: string | null }> {
+type BinaryCheck =
+  | { exists: true; path: string }
+  | { exists: false; path: null }
+
+async function checkBinaryExists(binary: string): Promise<BinaryCheck> {
   try {
     const path = Bun.which(binary)
     if (path) {
@@ -44,7 +48,7 @@ export async function checkAstGrepCli(): Promise<DependencyInfo> {
     }
   }
 
-  const version = await getBinaryVersion(binary.path!)
+  const version = await getBinaryVersion(binary.path)
 
   return {
     name: "AST-Grep CLI",
diff --git a/src/cli/run/poll-for-completion.ts b/src/cli/run/poll-for-completion.ts
index f393b5b9d..fe47a6e7f 100644
--- a/src/cli/run/poll-for-completion.ts
+++ b/src/cli/run/poll-for-completion.ts
@@ -2,7 +2,7 @@ import pc from "picocolors"
 import type { RunContext } from "./types"
 import type { EventState } from "./events"
 import { checkCompletionConditions } from "./completion"
-import { normalizeSDKResponse } from "../../shared"
+import { isRecord, normalizeSDKResponse } from "../../shared"
 
 const DEFAULT_POLL_INTERVAL_MS = 500
 const DEFAULT_REQUIRED_CONSECUTIVE = 1
@@ -11,6 +11,17 @@ const MIN_STABILIZATION_MS = 1_000
 const DEFAULT_EVENT_WATCHDOG_MS = 30_000 // 30 seconds
 const DEFAULT_SECONDARY_MEANINGFUL_WORK_TIMEOUT_MS = 60_000 // 60 seconds
 
+type SessionStatusMap = Record<string, { type?: string }>
+
+function isIncompleteTodo(value: unknown): boolean {
+  if (!isRecord(value)) {
+    return true
+  }
+
+  const status = value.status
+  return status !== "completed" && status !== "cancelled"
+}
+
 export interface PollOptions {
   pollIntervalMs?: number
   requiredConsecutive?: number
@@ -123,22 +134,18 @@ export async function pollForCompletion(
           path: { id: ctx.sessionID },
           query: { directory: ctx.directory },
         })
-        const children = normalizeSDKResponse(childrenRes, [] as unknown[])
+        const children = normalizeSDKResponse<unknown[]>(childrenRes, [])
         const todosRes = await ctx.client.session.todo({
           path: { id: ctx.sessionID },
           query: { directory: ctx.directory },
         })
-        const todos = normalizeSDKResponse(todosRes, [] as unknown[])
+        const todos = normalizeSDKResponse<unknown[]>(todosRes, [])
 
         const hasActiveChildren =
           Array.isArray(children) && children.length > 0
         const hasActiveTodos =
           Array.isArray(todos) &&
-          todos.some(
-            (t: unknown) =>
-              (t as { status?: string })?.status !== "completed" &&
-              (t as { status?: string })?.status !== "cancelled"
-          )
+          todos.some(isIncompleteTodo)
         const hasActiveWork = hasActiveChildren || hasActiveTodos
 
         if (hasActiveWork) {
@@ -189,10 +196,7 @@ async function getMainSessionStatus(
     const statusesRes = await ctx.client.session.status({
       query: { directory: ctx.directory },
     })
-    const statuses = normalizeSDKResponse(
-      statusesRes,
-      {} as Record<string, { type?: string }>
-    )
+    const statuses = normalizeSDKResponse<SessionStatusMap>(statusesRes, {})
     if (!(ctx.sessionID in statuses)) {
       return "idle"
     }
diff --git a/src/features/team-mode/team-runtime/delete-team.ts b/src/features/team-mode/team-runtime/delete-team.ts
index 201b44a63..88d4e3df4 100644
--- a/src/features/team-mode/team-runtime/delete-team.ts
+++ b/src/features/team-mode/team-runtime/delete-team.ts
@@ -103,8 +103,11 @@ export async function deleteTeam(
   const removedLayout = config.tmux_visualization && tmuxMgr !== undefined && deps.canVisualize()
   if (removedLayout) {
     const memberPaneIds = runtimeState.members
-      .filter((member) => member.agentType !== "leader" && member.tmuxPaneId)
-      .map((member) => member.tmuxPaneId!)
+      .flatMap((member) => (
+        member.agentType !== "leader" && member.tmuxPaneId
+          ? [member.tmuxPaneId]
+          : []
+      ))
 
     const cleanupTarget = runtimeState.tmuxLayout
       ? {
diff --git a/src/hooks/interactive-bash-session/hook.ts b/src/hooks/interactive-bash-session/hook.ts
index 86aa2f101..9e3398d28 100644
--- a/src/hooks/interactive-bash-session/hook.ts
+++ b/src/hooks/interactive-bash-session/hook.ts
@@ -2,7 +2,7 @@ import type { PluginInput } from "@opencode-ai/plugin";
 import { saveInteractiveBashSessionState, clearInteractiveBashSessionState } from "./storage";
 import { buildSessionReminderMessage } from "./constants";
 import type { InteractiveBashSessionState } from "./types";
-import { tokenizeCommand, findSubcommand, extractSessionNameFromTokens } from "./parser";
+import { parseTmuxCommand } from "./tmux-command-parser";
 import { getOrCreateState, isOmoSession, killAllTrackedSessions } from "./state-manager";
 import { subagentSessions } from "../../features/claude-code-session-state";
 import { resolveSessionEventID } from "../../shared/event-session-id";
@@ -60,8 +60,7 @@ export function createInteractiveBashSessionHook(ctx: PluginInput) {
     }
 
     const tmuxCommand = args.tmux_command;
-    const tokens = tokenizeCommand(tmuxCommand);
-    const subCommand = findSubcommand(tokens);
+    const { subCommand, sessionName } = parseTmuxCommand(tmuxCommand);
     const state = getOrCreateStateLocal(sessionID);
     let stateChanged = false;
 
@@ -74,13 +73,11 @@ export function createInteractiveBashSessionHook(ctx: PluginInput) {
     const isKillSession = subCommand === "kill-session";
     const isKillServer = subCommand === "kill-server";
 
-    const sessionName = extractSessionNameFromTokens(tokens, subCommand);
-
     if (isNewSession && isOmoSession(sessionName)) {
-      state.tmuxSessions.add(sessionName!);
+      state.tmuxSessions.add(sessionName);
       stateChanged = true;
     } else if (isKillSession && isOmoSession(sessionName)) {
-      state.tmuxSessions.delete(sessionName!);
+      state.tmuxSessions.delete(sessionName);
       stateChanged = true;
     } else if (isKillServer) {
       state.tmuxSessions.clear();
diff --git a/src/hooks/interactive-bash-session/parser.ts b/src/hooks/interactive-bash-session/parser.ts
deleted file mode 100644
index 0002d9312..000000000
--- a/src/hooks/interactive-bash-session/parser.ts
+++ /dev/null
@@ -1,118 +0,0 @@
-/**
- * Quote-aware command tokenizer with escape handling
- * Handles single/double quotes and backslash escapes
- */
-export function tokenizeCommand(cmd: string): string[] {
-  const tokens: string[] = []
-  let current = ""
-  let inQuote = false
-  let quoteChar = ""
-  let escaped = false
-
-  for (let i = 0; i < cmd.length; i++) {
-    const char = cmd[i]
-
-    if (escaped) {
-      current += char
-      escaped = false
-      continue
-    }
-
-    if (char === "\\") {
-      escaped = true
-      continue
-    }
-
-    if ((char === "'" || char === '"') && !inQuote) {
-      inQuote = true
-      quoteChar = char
-    } else if (char === quoteChar && inQuote) {
-      inQuote = false
-      quoteChar = ""
-    } else if (char === " " && !inQuote) {
-      if (current) {
-        tokens.push(current)
-        current = ""
-      }
-    } else {
-      current += char
-    }
-  }
-
-  if (current) tokens.push(current)
-  return tokens
-}
-
-/**
- * Normalize session name by stripping :window and .pane suffixes
- * e.g., "omo-x:1" -> "omo-x", "omo-x:1.2" -> "omo-x"
- */
-export function normalizeSessionName(name: string): string {
-  return name.split(":")[0].split(".")[0]
-}
-
-export function findFlagValue(tokens: string[], flag: string): string | null {
-  for (let i = 0; i < tokens.length - 1; i++) {
-    if (tokens[i] === flag) return tokens[i + 1]
-  }
-  return null
-}
-
-/**
- * Extract session name from tokens, considering the subCommand
- * For new-session: prioritize -s over -t
- * For other commands: use -t
- */
-export function extractSessionNameFromTokens(tokens: string[], subCommand: string): string | null {
-  if (subCommand === "new-session") {
-    const sFlag = findFlagValue(tokens, "-s")
-    if (sFlag) return normalizeSessionName(sFlag)
-    const tFlag = findFlagValue(tokens, "-t")
-    if (tFlag) return normalizeSessionName(tFlag)
-  } else {
-    const tFlag = findFlagValue(tokens, "-t")
-    if (tFlag) return normalizeSessionName(tFlag)
-  }
-  return null
-}
-
-/**
- * Find the tmux subcommand from tokens, skipping global options.
- * tmux allows global options before the subcommand:
- * e.g., `tmux -L socket-name new-session -s omo-x`
- * Global options with args: -L, -S, -f, -c, -T
- * Standalone flags: -C, -v, -V, etc.
- * Special: -- (end of options marker)
- */
-export function findSubcommand(tokens: string[]): string {
-  // Options that require an argument: -L, -S, -f, -c, -T
-  const globalOptionsWithArgs = new Set(["-L", "-S", "-f", "-c", "-T"])
-
-  let i = 0
-  while (i < tokens.length) {
-    const token = tokens[i]
-
-    // Handle end of options marker
-    if (token === "--") {
-      // Next token is the subcommand
-      return tokens[i + 1] ?? ""
-    }
-
-    if (globalOptionsWithArgs.has(token)) {
-      // Skip the option and its argument
-      i += 2
-      continue
-    }
-
-    if (token.startsWith("-")) {
-      // Skip standalone flags like -C, -v, -V
-      i++
-      continue
-    }
-
-    // Found the subcommand
-    return token
-  }
-
-  return ""
-}
diff --git a/src/hooks/interactive-bash-session/state-manager.ts b/src/hooks/interactive-bash-session/state-manager.ts
index c3a286421..70f737d11 100644
--- a/src/hooks/interactive-bash-session/state-manager.ts
+++ b/src/hooks/interactive-bash-session/state-manager.ts
@@ -2,21 +2,25 @@ import type { InteractiveBashSessionState } from "./types";
 import { loadInteractiveBashSessionState } from "./storage";
 import { OMO_SESSION_PREFIX } from "./constants";
 import { spawnWithWindowsHide } from "../../shared/spawn-with-windows-hide";
+import { log } from "../../shared/logger";
 
 export function getOrCreateState(sessionID: string, sessionStates: Map<string, InteractiveBashSessionState>): InteractiveBashSessionState {
-  if (!sessionStates.has(sessionID)) {
-    const persisted = loadInteractiveBashSessionState(sessionID);
-    const state: InteractiveBashSessionState = persisted ?? {
-      sessionID,
-      tmuxSessions: new Set<string>(),
-      updatedAt: Date.now(),
-    };
-    sessionStates.set(sessionID, state);
+  const existing = sessionStates.get(sessionID);
+  if (existing) {
+    return existing;
   }
-  return sessionStates.get(sessionID)!;
+
+  const persisted = loadInteractiveBashSessionState(sessionID);
+  const state: InteractiveBashSessionState = persisted ?? {
+    sessionID,
+    tmuxSessions: new Set<string>(),
+    updatedAt: Date.now(),
+  };
+  sessionStates.set(sessionID, state);
+  return state;
 }
 
-export function isOmoSession(sessionName: string | null): boolean {
+export function isOmoSession(sessionName: string | null): sessionName is string {
   return sessionName !== null && sessionName.startsWith(OMO_SESSION_PREFIX);
 }
 
@@ -30,6 +34,11 @@ export async function killAllTrackedSessions(
         stderr: "ignore",
       });
       await proc.exited;
-    } catch {}
+    } catch (error) {
+      log("[interactive-bash-session] failed to kill tracked tmux session", {
+        error: error instanceof Error ? error.message : String(error),
+        sessionName,
+      });
+    }
   }
 }
diff --git a/src/hooks/read-image-resizer/hook.ts b/src/hooks/read-image-resizer/hook.ts
index a537dca87..56df0c189 100644
--- a/src/hooks/read-image-resizer/hook.ts
+++ b/src/hooks/read-image-resizer/hook.ts
@@ -189,8 +189,8 @@ export function createReadImageResizerHook(_ctx: PluginInput) {
         }
       }
 
-      if (attachmentsToRemove.length > 0) {
-        const rawAttachments = outputRecord.attachments as unknown[]
+      if (attachmentsToRemove.length > 0 && Array.isArray(outputRecord.attachments)) {
+        const rawAttachments = outputRecord.attachments
         for (const toRemove of attachmentsToRemove) {
           const removeIndex = rawAttachments.indexOf(toRemove)
           if (removeIndex !== -1) {
diff --git a/src/hooks/session-recovery/storage/messages-reader.ts b/src/hooks/session-recovery/storage/messages-reader.ts
index ecedf2400..094a1b03b 100644
--- a/src/hooks/session-recovery/storage/messages-reader.ts
+++ b/src/hooks/session-recovery/storage/messages-reader.ts
@@ -62,7 +62,7 @@ export async function readMessagesFromSDK(
 ): Promise<StoredMessageMeta[]> {
   try {
     const response = await client.session.messages({ path: { id: sessionID } })
-    const data = normalizeSDKResponse(response, [] as unknown[], {
+    const data = normalizeSDKResponse<unknown[]>(response, [], {
       preferResponseOnMissingData: true,
     })
     if (!Array.isArray(data)) return []
diff --git a/src/hooks/todo-continuation-enforcer/todo-continuation-enforcer.test.ts b/src/hooks/todo-continuation-enforcer/todo-continuation-enforcer.test.ts
index bb1a56d39..442ef008c 100644
--- a/src/hooks/todo-continuation-enforcer/todo-continuation-enforcer.test.ts
+++ b/src/hooks/todo-continuation-enforcer/todo-continuation-enforcer.test.ts
@@ -1190,16 +1190,9 @@ describe("todo-continuation-enforcer", () => {
     // then - continuation injected (non-abort errors don't block)
     expect(promptCalls.length).toBe(1)
   }, { timeout: 15000 })
-
-
-
-
-
-  // ============================================================
   // API-BASED ABORT DETECTION TESTS
   // These tests verify that abort is detected by checking
   // the last assistant message's error field via session.messages API
-  // ============================================================
 
   test("should skip injection when last assistant message has MessageAbortedError", async () => {
     // given - session where last assistant message was aborted
@@ -1673,11 +1666,9 @@ describe("todo-continuation-enforcer", () => {
      expect(promptCalls[0].model).toEqual({ providerID: "openai", modelID: "gpt-5.4" })
   })
 
-  // ============================================================
   // COMPACTION AGENT FILTERING TESTS
   // These tests verify that compaction agent messages are filtered
   // when resolving agent info, preventing infinite continuation loops
-  // ============================================================
 
   test("should skip injection while the latest message is from the compaction agent", async () => {
     // given - session where the latest activity is still the compaction assistant turn
@@ -2102,11 +2093,9 @@ describe("todo-continuation-enforcer", () => {
     expect(promptCalls).toHaveLength(1)
   }, { timeout: 20000 })
 
-  // ============================================================
   // TOKEN-LIMIT ERROR DETECTION TESTS (#2462)
   // These tests verify that the enforcer does NOT retry continuation
   // when the model returns a token-limit / context-length error.
-  // ============================================================
 
   test("should stop continuation when session.error carries a ContextLengthError", async () => {
     // given - session with incomplete todos
diff --git a/src/plugin-handlers/command-config-handler.ts b/src/plugin-handlers/command-config-handler.ts
index b6dda6178..3d5fafd2c 100644
--- a/src/plugin-handlers/command-config-handler.ts
+++ b/src/plugin-handlers/command-config-handler.ts
@@ -43,8 +43,8 @@ export async function applyCommandConfig(params: {
   const includeClaudeSkills = params.pluginConfig.claude_code?.skills ?? true;
 
   const externalSkillPlugin = detectExternalSkillPlugin(params.ctx.directory);
-  if (includeClaudeSkills && externalSkillPlugin.detected) {
-    log(getSkillPluginConflictWarning(externalSkillPlugin.pluginName!));
+  if (includeClaudeSkills && externalSkillPlugin.detected && externalSkillPlugin.pluginName) {
+    log(getSkillPluginConflictWarning(externalSkillPlugin.pluginName));
   }
 
   const [
diff --git a/src/plugin/hooks/create-session-hooks.ts b/src/plugin/hooks/create-session-hooks.ts
index ae2d7bb11..69208820a 100644
--- a/src/plugin/hooks/create-session-hooks.ts
+++ b/src/plugin/hooks/create-session-hooks.ts
@@ -101,8 +101,8 @@ export function createSessionHooks(args: {
   if (isHookEnabled("session-notification")) {
     const forceEnable = pluginConfig.notification?.force_enable ?? false
     const externalNotifier = detectExternalNotificationPlugin(ctx.directory)
-    if (externalNotifier.detected && !forceEnable) {
-      log(getNotificationConflictWarning(externalNotifier.pluginName!))
+    if (externalNotifier.detected && externalNotifier.pluginName && !forceEnable) {
+      log(getNotificationConflictWarning(externalNotifier.pluginName))
     } else {
       sessionNotification = safeHook("session-notification", () => createSessionNotification(ctx))
     }
diff --git a/src/shared/log-legacy-plugin-startup-warning.ts b/src/shared/log-legacy-plugin-startup-warning.ts
index d1151b122..a1d242adf 100644
--- a/src/shared/log-legacy-plugin-startup-warning.ts
+++ b/src/shared/log-legacy-plugin-startup-warning.ts
@@ -16,7 +16,7 @@ export function logLegacyPluginStartupWarning(deps: LogLegacyPluginStartupWarnin
   const migrateLegacyPluginEntryFn = deps.migrateLegacyPluginEntry ?? migrateLegacyPluginEntry
 
   const result = checkForLegacyPluginEntryFn()
-  if (!result.hasLegacyEntry) {
+  if (!result.hasLegacyEntry || !result.configPath) {
     return
   }
 
@@ -34,7 +34,7 @@ export function logLegacyPluginStartupWarning(deps: LogLegacyPluginStartupWarnin
     + ` Attempting auto-migration...`,
   )
 
-  const migrated = migrateLegacyPluginEntryFn(result.configPath!)
+  const migrated = migrateLegacyPluginEntryFn(result.configPath)
   if (migrated) {
     console.warn(`[oh-my-openagent] Auto-migrated opencode.json: ${result.legacyEntries.join(", ")} -> ${suggestedEntries.join(", ")}`)
   } else {
diff --git a/src/tools/background-task/create-background-cancel.ts b/src/tools/background-task/create-background-cancel.ts
index 30f73837f..2347ebcfc 100644
--- a/src/tools/background-task/create-background-cancel.ts
+++ b/src/tools/background-task/create-background-cancel.ts
@@ -15,10 +15,6 @@ export function createBackgroundCancel(manager: BackgroundManager, _client: Back
       try {
         const cancelAll = args.all === true
 
-        if (!cancelAll && !args.taskId) {
-          return `[ERROR] Invalid arguments: Either provide a taskId or set all=true to cancel all running tasks.`
-        }
-
         if (cancelAll) {
           const tasks = manager.getAllDescendantTasks(toolContext.sessionID)
           const cancellableTasks = tasks.filter((t: { status: string }) => t.status === "running" || t.status === "pending")
@@ -74,9 +70,14 @@ ${tableRows}
 ${resumeSection}`
         }
 
-        const task = manager.getTask(args.taskId!)
+        const taskId = args.taskId
+        if (!taskId) {
+          return `[ERROR] Invalid arguments: Either provide a taskId or set all=true to cancel all running tasks.`
+        }
+
+        const task = manager.getTask(taskId)
         if (!task) {
-          return `[ERROR] Task not found: ${args.taskId}`
+          return `[ERROR] Task not found: ${taskId}`
         }
 
         if (task.status !== "running" && task.status !== "pending") {
diff --git a/src/tools/delegate-task/tools.test.ts b/src/tools/delegate-task/tools.test.ts
index a10711228..7261c1d88 100644
--- a/src/tools/delegate-task/tools.test.ts
+++ b/src/tools/delegate-task/tools.test.ts
@@ -3518,7 +3518,6 @@ describe("sisyphus-task", () => {
       expect(actualModel).not.toBe(inheritedModel)
     })
 
-    // ===== TESTS FOR resolveModel() INTEGRATION (TDD GREEN) =====
     // These tests verify the NEW behavior where categories do NOT have default models
 
     test("FIXED: category built-in model takes precedence over inheritedModel", () => {
diff --git a/src/tools/look-at/look-at-arguments.ts b/src/tools/look-at/look-at-arguments.ts
index 4a2d978fb..a62241b2f 100644
--- a/src/tools/look-at/look-at-arguments.ts
+++ b/src/tools/look-at/look-at-arguments.ts
@@ -13,10 +13,11 @@ export function normalizeArgs(args: LookAtArgsWithAlias): LookAtArgs {
 }
 
 export function validateArgs(args: LookAtArgs): string | null {
-  const hasFilePath = Boolean(args.file_path && args.file_path.length > 0)
+  const filePath = args.file_path
+  const hasFilePath = Boolean(filePath && filePath.length > 0)
   const hasImageData = Boolean(args.image_data && args.image_data.length > 0)
 
-  if (hasFilePath && /^https?:\/\//i.test(args.file_path!)) {
+  if (filePath && /^https?:\/\//i.test(filePath)) {
     return "Error: Remote URLs are not supported for file_path. Download the file first or use a local path."
   }
   if (!hasFilePath && !hasImageData) {
diff --git a/src/tools/lsp/lsp-client-transport.ts b/src/tools/lsp/lsp-client-transport.ts
index e8b34e706..05d1d0f18 100644
--- a/src/tools/lsp/lsp-client-transport.ts
+++ b/src/tools/lsp/lsp-client-transport.ts
@@ -136,22 +136,27 @@ export class LSPClientTransport {
       throw new Error(`LSP server already exited (code: ${this.proc?.exitCode})` + (stderr ? `\nstderr: ${stderr}` : ""))
     }
 
-    let timeoutId: ReturnType<typeof setTimeout>
+    let timeoutId: ReturnType<typeof setTimeout> | undefined
     const timeoutPromise = new Promise<never>((_, reject) => {
       timeoutId = setTimeout(() => {
         const stderr = this.stderrBuffer.slice(-5).join("\n")
         reject(new Error(`LSP request timeout (method: ${method})` + (stderr ? `\nrecent stderr: ${stderr}` : "")))
       }, this.REQUEST_TIMEOUT)
     })
+    const clearRequestTimeout = (): void => {
+      if (timeoutId !== undefined) {
+        clearTimeout(timeoutId)
+      }
+    }
 
     const requestPromise = this.connection.sendRequest(method, ...args) as Promise<T>
 
     try {
       const result = await Promise.race([requestPromise, timeoutPromise])
-      clearTimeout(timeoutId!)
+      clearRequestTimeout()
       return result
     } catch (error) {
-      clearTimeout(timeoutId!)
+      clearRequestTimeout()
       throw error
     }
   }
diff --git a/src/tools/lsp/symbols-tool.ts b/src/tools/lsp/symbols-tool.ts
index 0c4ca130b..3af960731 100644
--- a/src/tools/lsp/symbols-tool.ts
+++ b/src/tools/lsp/symbols-tool.ts
@@ -22,12 +22,13 @@ export const lsp_symbols: ToolDefinition = tool({
       const scope = args.scope ?? "document"
 
       if (scope === "workspace") {
-        if (!args.query) {
+        const query = args.query
+        if (!query) {
           return "Error: 'query' is required for workspace scope"
         }
 
         const result = await withLspClient(args.filePath, async (client) => {
-          return (await client.workspaceSymbols(args.query!)) as SymbolInfo[] | null
+          return (await client.workspaceSymbols(query)) as SymbolInfo[] | null
         })
 
         if (!result || result.length === 0) {