refactor: replace vim.uv.* asserts with warn-and-bail

lua/core/keymap.lua

@@ -58,8 +58,8 @@ local function delete_buffer(force)
     if #buffers < 2 then
         return
     end
-    local b1 = assert(buffers[1])
-    local b2 = assert(buffers[2])
+    local b1 = buffers[1] --[[@as -nil]]
+    local b2 = buffers[2] --[[@as -nil]]
 
     local current = tonumber(b1:match("^%s*(%d+)")) --[[@as integer?]]
     local previous = tonumber(b2:match("^%s*(%d+)")) --[[@as integer?]]

lua/pack.lua

@@ -193,7 +193,11 @@ function M.watch()
         return
     end
 
-    watcher = assert(vim.uv.new_fs_event())
+    local w, err = vim.uv.new_fs_event()
+    if not w then
+        util.warning("pack: failed to create fs_event: %s", err)
+        return
+    end
     local on_change, handle = util.keyed_debounce(
         ---@param filename string
         function(filename)
@@ -210,16 +214,15 @@ function M.watch()
         end,
         200
     )
-    on_change_handle = handle
 
-    assert(watcher:start(
+    local ok, err = w:start(
         plugins_dir,
         {},
         ---@param err string?
         ---@param filename string
         function(err, filename)
             if err then
-                log.error("Watch error: %s", err)
+                log.error("pack: watch error for %s: %s", filename, err)
                 return
             end
             if not filename or not filename:match("%.lua$") then
@@ -227,7 +230,15 @@ function M.watch()
             end
             on_change(filename)
         end
-    ))
+    )
+    if not ok then
+        util.warning("pack: failed to watch %s: %s", plugins_dir, err)
+        w:close()
+        handle:close()
+        return
+    end
+    on_change_handle = handle
+    watcher = w
 end
 
 function M.unwatch()

lua/util.lua

@@ -304,7 +304,20 @@ end
 ---@param delay integer
 ---@return F, ow.Util.DebounceHandle
 function M.debounce(fn, delay)
-    local timer = assert(vim.uv.new_timer())
+    local timer, err = vim.uv.new_timer()
+    if not timer then
+        M.warning("debounce: failed to create timer: %s", err)
+        local noop = function() end
+        return fn,
+            {
+                cancel = noop,
+                flush = noop,
+                pending = function()
+                    return false
+                end,
+                close = noop,
+            }
+    end
     local args ---@type table?
     local gen = 0
     local fired_gen = 0