fix: detect opencode process when command name is 'bun' instead of 'opencode'

Fixes #83

When opencode is installed via Nix or launched with Bun, the process
name in lsof appears as 'bun' instead of 'opencode', causing the
plugin to fail to auto-detect the running server.

This changes the detection logic to:
1. Use pgrep to find PIDs by command line pattern 'opencode run'
2. Use lsof on the specific PIDs to get their listening ports

This approach is more robust and works regardless of how opencode
was installed or launched (node, bun, binary, etc.).

Author: jerome-benoit

lua/opencode/cli/server.lua

@@ -29,44 +29,55 @@ local function find_servers()
       0
     )
   end
-  -- Going straight to `lsof` relieves us of parsing `ps` and all the non-portable 'opencode'-containing processes it might return.
-  -- With these flags, we'll only get processes that are listening on TCP ports and have 'opencode' in their command name.
-  -- i.e. pretty much guaranteed to be just opencode server processes.
-  -- `-w` flag suppresses warnings about inaccessible filesystems (e.g. Docker FUSE).
-  local output = exec("lsof -w -iTCP -sTCP:LISTEN -P -n | grep opencode")
-  if output == "" then
+
+  -- Find PIDs by command line pattern (handles process names like 'bun', 'node', etc.)
+  local pgrep_output = exec("pgrep -f 'opencode run' 2>/dev/null || true")
+  if pgrep_output == "" then
     error("No `opencode` processes", 0)
   end
 
   local servers = {}
-  for line in output:gmatch("[^\r\n]+") do
-    -- lsof output: COMMAND PID USER FD TYPE DEVICE SIZE/OFF NODE NAME
-    local parts = vim.split(line, "%s+")
-
-    local pid = tonumber(parts[2])
-    local port = tonumber(parts[9]:match(":(%d+)$")) -- Extract port from NAME field (which is e.g. "127.0.0.1:12345")
-    if not pid or not port then
-      error("Couldn't parse `opencode` PID and port from `lsof` entry: " .. line, 0)
-    end
-
-    local cwd = exec("lsof -w -a -p " .. pid .. " -d cwd"):match("%s+(/.*)$")
-    if not cwd then
-      error("Couldn't determine CWD for PID: " .. pid, 0)
+  for pid_str in pgrep_output:gmatch("[^\r\n]+") do
+    local pid = tonumber(pid_str)
+    if pid then
+      -- `-w` suppresses warnings about inaccessible filesystems (e.g. Docker FUSE)
+      local lsof_output = exec("lsof -w -iTCP -sTCP:LISTEN -P -n -a -p " .. pid .. " 2>/dev/null || true")
+      
+      if lsof_output ~= "" then
+        for line in lsof_output:gmatch("[^\r\n]+") do
+          local parts = vim.split(line, "%s+")
+          
+          if parts[1] ~= "COMMAND" then -- Skip header
+            local port = parts[9] and parts[9]:match(":(%d+)$") -- Extract port from "127.0.0.1:12345"
+            if port then
+              port = tonumber(port)
+              
+              local cwd = exec("lsof -w -a -p " .. pid .. " -d cwd 2>/dev/null || true"):match("%s+(/.*)$")
+              if cwd then
+                table.insert(
+                  servers,
+                  ---@class Server
+                  ---@field pid number
+                  ---@field port number
+                  ---@field cwd string
+                  {
+                    pid = pid,
+                    port = port,
+                    cwd = cwd,
+                  }
+                )
+              end
+            end
+          end
+        end
+      end
     end
+  end
 
-    table.insert(
-      servers,
-      ---@class Server
-      ---@field pid number
-      ---@field port number
-      ---@field cwd string
-      {
-        pid = pid,
-        port = port,
-        cwd = cwd,
-      }
-    )
+  if #servers == 0 then
+    error("No `opencode` processes with listening ports found", 0)
   end
+
   return servers
 end