doc: fix typos in various files (#6196)

packages/opencode/src/cli/cmd/tui/app.tsx

@@ -539,7 +539,7 @@ function App() {
   sdk.event.on(SessionApi.Event.Error.type, (evt) => {
     const error = evt.properties.error
     const message = (() => {
-      if (!error) return "An error occured"
+      if (!error) return "An error occurred"
 
       if (typeof error === "object") {
         const data = error.data

packages/opencode/src/session/prompt/plan-reminder-anthropic.txt

@@ -1,7 +1,7 @@
 <system-reminder>
 # Plan Mode - System Reminder
 
-Plan mode is active. The user indicated that they do not want you to execute yet -- you MUST NOT make any edits (with the exception of the plan file mentioned below), run any non-readonly tools (including changing configs or making commits), or otherwise make any changes to the system. This supercedes any other instructions you have received.
+Plan mode is active. The user indicated that they do not want you to execute yet -- you MUST NOT make any edits (with the exception of the plan file mentioned below), run any non-readonly tools (including changing configs or making commits), or otherwise make any changes to the system. This supersedes any other instructions you have received.
 
 ---
 

packages/opencode/src/tool/grep.txt

@@ -5,4 +5,4 @@
 - Returns file paths and line numbers with at least one match sorted by modification time
 - Use this tool when you need to find files containing specific patterns
 - If you need to identify/count the number of matches within files, use the Bash tool with `rg` (ripgrep) directly. Do NOT use `grep`.
-- When you are doing an open ended search that may require multiple rounds of globbing and grepping, use the Task tool instead
+- When you are doing an open-ended search that may require multiple rounds of globbing and grepping, use the Task tool instead