Preview files inside an archive, and search every volume from an index

The archive preview could say what a zip held but not show any of it, and the search could only answer "is it here?" for the folder tree the user was standing in. Both are now answered.

ArchiveEngine gains a single-entry reader: a ZIP the backend can seek jumps straight at the entry's data through the central directory, 7z scans its index, a streaming container decompresses past whatever is in front of the entry, and a compression wrapper has exactly one entry whose name is derived from the archive's own. extractEntry is rewritten on top of it, so there is one implementation of "reach this entry" rather than two that could disagree, and the now-dead extractFromZip and only= parameters are removed.

A tap on a row now previews and the row's action extracts, which is what a row means everywhere else in this app. Text and markup are read into memory, so the commonest question - what does this readme say - writes nothing at all and works in both storage modes. Everything else needs a file a decoder can open, so the entry is copied into the app's own cache, one folder per preview and under its own name so the viewer's title bar does not read copy-0.png, and deleted when the preview closes with a non-recursive delete. The copy is a real path, so image, PDF and media previews work even in the SAF fallback, where the browsed files cannot be previewed at all. A copy has no file to save back to, so the text editor shows no Save and markup offers no editor; closing returns to the archive rather than out of it.

SearchIndex is a small port over SQLite beside the trash index, inheriting that one's doctrine that an index is not the truth: a reader drops rows whose file has gone and forgets them, freshness is reported rather than assumed, and a volume's rows are replaced wholesale so an interrupted pass leaves the previous listing rather than half of this one. Timestamps are written only when a pass finishes, so a walk cut short by a new keystroke reads as older than it is, which is the safe direction to be wrong in. Names are matched with NameMatcher's semantics translated into LIKE - substring, anchored glob, and a literal % or _ escaped - because a search that quietly widens what was typed is what an index does badly.

The search field gains a scope toggle, and every search everywhere carries the age of the index and a way to rebuild it, because a search that silently omits what arrived since the last walk is worse than one that spends a minute being sure. Rows are written in batches of 500 and the counter reported every 100, since a row reading "0 files" for the whole first second reads as nothing happening. Deliberately not a foreground service: a pass runs while the screen is up and stops when it is not.

Verified on the API 35 phone rather than inferred: a .txt and a .png inside a real zip, both previewed from the archive list with their own names, the copy gone on close and the archive list restored behind it; then the first search building the index with a full walk, and a search after an app restart answering instantly and finding a file in Download/cline-zip while browsing Internal storage. Watching it caught two lies, both fixed here: the empty state claimed "Nothing matches" while the index was still being written, and two progress bars stacked on each other.

268 JVM tests, lint clean, release APK builds and installs. The store listing gains the archive preview and the scoped search and is re-measured at 2730/4000.

docs/ROADMAP.md

@@ -19,7 +19,7 @@ Legend: ✅ done · 🚧 in progress · ⏳ not started · 💡 candidate (propo
 | M7 | On-device validation & hardening | ✅ | Run on a real **Xiaomi M2101K7AG** (Android 12 / MIUI V140) — see [EDGE_CASE_TESTING](EDGE_CASE_TESTING.md). Verified on hardware: the first-run permission prompt, granting "All files access" while the app is alive (picked up on resume), browsing real storage, the text editor's read **and** write path (independently checked with `adb shell cat`), the storage-usage screen, landscape layout, and **graceful degradation when access is revoked mid-use**. Found and fixed two real defects: misleading first-run copy ("Full access was declined" on a device where nothing had been declined), and a usage screen that stayed blank for **~45–60 s** on a 55 GB volume — now one listing per directory instead of a `stat` per node, with rows streamed out as they are measured. **142 JVM tests** |
 | M8 | Localisation groundwork | ✅ | Every user-visible string is in `res/values/strings.xml` with real `<plurals>`, and `text/TextRes.kt` maps **both** `OperationKind` and `FileKind` onto resources so the screen, the notification and the details sheet cannot drift. The audit found a genuine miss: the details sheet rendered `FileKind.name`, i.e. untranslatable English — now a resource. `isPseudoLocalesEnabled = true` on the debug build makes "did every string come from resources?" mechanically checkable; verified `en-rXA` is present in the debug APK and the flag is debug-only. Byte units and the timestamp pattern are deliberately unlocalised, and the README says why. **142 JVM tests** |
 | M9 | Monetisation | ✅ | **Decided: one-time paid — €4.49 base with a 14-day launch price of €2.29**, both set in the Play Console (*Products › App pricing*), so there is **no Billing client, no `com.android.vending.BILLING` permission and no purchase code**. Rationale, market anchors and Console steps: [MONETISATION](MONETISATION.md). Verified against the release APK: zero billing and zero `INTERNET` references. **The price must be set before the first upload** — Play allows paid → free but never free → paid |
-| M10 | Store assets | ✅ | Name decided: **Plain Files** (one string; `applicationId` already locked). `tools/make-store-assets.sh` renders the 512×512 **RGBA** icon and the 1024×500 **RGB** feature graphic from the app's own vectors, so the store icon *is* the launcher icon; `tools/make-store-screenshots.sh` normalises `adb` captures to Play's 2:1 cap per form factor (phone crop default 93/130 px, tablets 0). [STORE_LISTING](STORE_LISTING.md) carries length-checked copy (name 11/30, short 67/80, full 2192/4000), the permissions paragraph the `MANAGE_EXTERNAL_STORAGE` declaration requires, and the graphics table. The feature graphic's copy was verified to survive Play's centre-square crop by cropping the rendered PNG. **Screenshots captured:** 5 phone (1080×2160), 4 on a 7-inch tablet (1200×1920) and 4 on a 10-inch tablet (2560×1600), all 24-bit RGB, inside the 2:1 cap. The tablet sets came from AOSP AVDs. The normaliser refuses a capture whose app area is blank, which is how a pure-background capture was caught before it reached the listing |
+| M10 | Store assets | ✅ | Name decided: **Plain Files** (one string; `applicationId` already locked). `tools/make-store-assets.sh` renders the 512×512 **RGBA** icon and the 1024×500 **RGB** feature graphic from the app's own vectors, so the store icon *is* the launcher icon; `tools/make-store-screenshots.sh` normalises `adb` captures to Play's 2:1 cap per form factor (phone crop default 93/130 px, tablets 0). [STORE_LISTING](STORE_LISTING.md) carries length-checked copy (name 11/30, short 67/80, full 2730/4000), the permissions paragraph the `MANAGE_EXTERNAL_STORAGE` declaration requires, and the graphics table. The feature graphic's copy was verified to survive Play's centre-square crop by cropping the rendered PNG. **Screenshots captured:** 5 phone (1080×2160), 4 on a 7-inch tablet (1200×1920) and 4 on a 10-inch tablet (2560×1600), all 24-bit RGB, inside the 2:1 cap. The tablet sets came from AOSP AVDs. The normaliser refuses a capture whose app area is blank, which is how a pure-background capture was caught before it reached the listing |
 
 ## Key decisions