v0.7.0: add XMP sidecars

README.md

@@ -21,6 +21,7 @@ For a practical step-by-step manual with recommended backup workflows, recovery
 - Deduplicated failure management with `failures list`, `failures clear`, and `retry-failed --clear-on-success`.
 - Verification, reporting, and diff commands for backup integrity.
 - Status command for quick backup summaries.
+- Opt-in XMP sidecar metadata with `--sidecar xmp`.
 - Script-friendly exit codes and optional JSON summaries.
 - 100% test coverage for the Go CLI and parsing layers.
 
@@ -276,6 +277,7 @@ Common flags for `export` and `backup-all`:
 - `--min-size <n>`: filter by estimated pixel count.
 - `--max-size <n>`: filter by estimated pixel count.
 - `--format jpeg|heic|png`: preview format hint. Current bridge output is still the existing preview path; non-JPEG bridge output is future work.
+- `--sidecar none|xmp`: write opt-in XMP metadata sidecars next to exported files.
 - `--date-template <template>`: append date folders based on creation date, for example `YYYY/MM/DD`.
 
 `backup-all` also supports:
@@ -328,6 +330,23 @@ With SQLite manifest mode, logs are written to the `logs` table in `downloads.db
 
 Logged events include session start/end, completed exports, skipped assets, and failures. Each event includes timestamp, level, event name, asset ID, album, filename, size, cloud state, duration, and message where available.
 
+## XMP Sidecars
+
+Write archival metadata sidecars with:
+
+```bash
+photoscli export --album-id "Vacation" --out ./Vacation --sidecar xmp
+```
+
+Sidecars are opt-in and use the exported file basename:
+
+```text
+IMG_0001.jpg -> IMG_0001.xmp
+IMG_0001.HEIC -> IMG_0001.xmp
+```
+
+The XMP contains photoscli metadata such as asset ID, filenames, album, manifest path, media type, dimensions, favorite state, cloud state, export mode, version, exported timestamp, size, and creation date when available. If `--sidecar xmp` is explicitly selected and the sidecar cannot be written, that asset is treated as failed.
+
 ## Failure Tracking
 
 Failed exports are deduplicated by asset ID and stored in: