container: use absolute for pathname

This is simultaneously more efficient and less error-prone. This change caused minor API changes in multiple other packages.

Signed-off-by: Ophestra <cat@gensokyo.uk>

hst/paths.go

@@ -1,11 +1,15 @@
 package hst
 
+import "hakurei.app/container"
+
 // Paths contains environment-dependent paths used by hakurei.
 type Paths struct {
+	// temporary directory returned by [os.TempDir] (usually `/tmp`)
+	TempDir *container.Absolute `json:"temp_dir"`
 	// path to shared directory (usually `/tmp/hakurei.%d`)
-	SharePath string `json:"share_path"`
+	SharePath *container.Absolute `json:"share_path"`
 	// XDG_RUNTIME_DIR value (usually `/run/user/%d`)
-	RuntimePath string `json:"runtime_path"`
+	RuntimePath *container.Absolute `json:"runtime_path"`
 	// application runtime directory (usually `/run/user/%d/hakurei`)
-	RunDirPath string `json:"run_dir_path"`
+	RunDirPath *container.Absolute `json:"run_dir_path"`
 }