Add exclude patterns, snapshot prune, and other improvements

- Implement exclude patterns with anchored pattern support:
  - Patterns starting with / only match from root of source dir
  - Unanchored patterns match anywhere in path
  - Support for glob patterns (*.log, .*, **/*.pack)
  - Directory patterns skip entire subtrees
  - Add gobwas/glob dependency for pattern matching
  - Add 16 comprehensive tests for exclude functionality

- Add snapshot prune command to clean orphaned data:
  - Removes incomplete snapshots from database
  - Cleans orphaned files, chunks, and blobs
  - Runs automatically at backup start for consistency

- Add snapshot remove command for deleting snapshots

- Add VAULTIK_AGE_SECRET_KEY environment variable support

- Fix duplicate fx module provider in restore command

- Change snapshot ID format to hostname_YYYY-MM-DDTHH:MM:SSZ

cmd/vaultik/main.go

@@ -1,9 +1,41 @@
 package main
 
 import (
+	"os"
+	"runtime"
+	"runtime/pprof"
+
 	"git.eeqj.de/sneak/vaultik/internal/cli"
 )
 
 func main() {
+	// CPU profiling: set VAULTIK_CPUPROFILE=/path/to/cpu.prof
+	if cpuProfile := os.Getenv("VAULTIK_CPUPROFILE"); cpuProfile != "" {
+		f, err := os.Create(cpuProfile)
+		if err != nil {
+			panic("could not create CPU profile: " + err.Error())
+		}
+		defer func() { _ = f.Close() }()
+		if err := pprof.StartCPUProfile(f); err != nil {
+			panic("could not start CPU profile: " + err.Error())
+		}
+		defer pprof.StopCPUProfile()
+	}
+
+	// Memory profiling: set VAULTIK_MEMPROFILE=/path/to/mem.prof
+	if memProfile := os.Getenv("VAULTIK_MEMPROFILE"); memProfile != "" {
+		defer func() {
+			f, err := os.Create(memProfile)
+			if err != nil {
+				panic("could not create memory profile: " + err.Error())
+			}
+			defer func() { _ = f.Close() }()
+			runtime.GC() // get up-to-date statistics
+			if err := pprof.WriteHeapProfile(f); err != nil {
+				panic("could not write memory profile: " + err.Error())
+			}
+		}()
+	}
+
 	cli.CLIEntry()
 }