F1 steps 2-6: the Storage App, its viewers, and Maintenance moved in (#3)

The Storage App browses the SD card: folders first with sizes and dates,
three sorts, one item at a time with a clipboard (c, x, v), rename, delete
after counting what's inside, new folder, details. A listing holds 256
entries and says when a folder has more.

FileOps does the card's work for the App and the console alike, one
operation at a time on the storage task in turns of about 150 ms, so Logs
and Captures are still written during a long copy. A copy shows progress,
can be cancelled (what it wrote is taken back) and compares sizes after.
The read-only rules are checked there: the firmware's top-level folders,
/gemini/cache, and files being written (a Track, a Capture, an upload,
today's IRC Logs). A listing reads the folder straight from FatFs: through
the Arduino File, 329 entries took over two seconds.

Viewers by type: text read a screen at a time whatever the file's size
(logs open at the end), a hex dump, a Capture's packets as the LoRa Scanner
lists them, a Track's summary, and an Update File checked as an install
would check it, without writing anything. Tab shows any file as hex or text.

Settings > Storage is gone: usage, Storage Clean-up and Erase are the App's
Maintenance, behind a warning. The Storage Warning points there.

The Clock sets the system time whatever its source, so files are dated
correctly with a GNSS Fix alone (Q137).

Console: cp, mv, mkdir, du, cancel; rm takes folders and follows the rules;
ls shows dates; Debug Builds get `sd fill`.

424 host tests. Checked on the device: docs/milestones/F1.md.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01EhqxQ49eCju4CzKYNjZzwT

docs/milestones/F1.md

@@ -1,6 +1,6 @@
 # F1 — Files and Notes
 
-**Status:** in progress (branch `f1`): the Storage App (issue #3) is being built. Notes (#19) and the card as a USB drive (#1) come after.
+**Status:** in progress (branch `f1`): the Storage App (issue #3) is built and checked on the device, not merged yet. Notes (#19) and the card as a USB drive (#1) come after.
 
 **Goal:** get at what's on the SD card from the device itself: browse it, look inside the files the firmware writes, copy, move, rename and delete, and keep notes. A side milestone, like G1 and S1; Files and Notes were M3's original second half (Q30, Q89).
 
@@ -34,7 +34,7 @@ Until now the card could be looked at only through the Debug Console (`ls`, `get
 - A file can be copied, moved, renamed and deleted, and a folder too; a new folder can be made. Each destructive action asks first; a copy shows progress and can be cancelled.
 - The read-only rules of Q130 hold, with a reason given when something is refused.
 - Each viewer of Q134 opens its type, and a 1 MB text file scrolls without loading whole.
-- Maintenance shows the card's usage and does what Settings > Storage did, behind its warning; Settings no longer has a Storage row; the Storage Warning opens the App's Maintenance.
+- Maintenance shows the card's usage and does what Settings > Storage did, behind its warning; Settings no longer has a Storage row; the Storage Warning points at the Storage App.
 - A file written with only a GNSS Fix (no Wi-Fi) is dated correctly.
 - Free heap stays above the floors with the App open, Wi-Fi and IRC on TLS.
 
@@ -46,3 +46,41 @@ Until now the card could be looked at only through the Debug Console (`ls`, `get
 4. **Maintenance:** usage, Clean-up and Erase moved in from Settings, with the warning.
 5. **Viewers:** text, hex, `.pcap`, `.gpx`, `.ota`.
 6. **Checks on the device**, recorded here.
+
+### As built
+
+- **`FileOps`** (`src/services/file_ops`) does the card's work for the App and for the console alike: list, count, copy, move, delete, new folder. One operation at a time on the storage task, **in turns of about 150 ms** that queue themselves again, so Log lines and a Capture are written in between. The rules of Q130 are checked there, whoever asks.
+- **A listing reads the folder straight from FatFs.** Through the Arduino `File`, every entry was looked up by name again for its size and again for its date: 329 entries took over two seconds. One pass now, and it's there before the screen has redrawn. Counting, copying and deleting still walk with `File`; they show progress and can be stopped.
+- **A copy shows its progress in a box in the App**, not a Toast (Q133): it has a bar and says Back cancels. A cancelled or failed copy deletes what it had written. The copy gets today's date, like `cp`.
+- **The viewers** (`src/apps/file_viewer`, models in `lib/files`): text through `TextPager`, which reads about a kilobyte around the screen and wraps at spaces, 38 columns; going back a line wraps the paragraph before again, so a file reads the same in both directions. A `.pcap`, a `.gpx` and an `.ota` are read through once by a storage job, in the same 150 ms turns. An Update File is fed to the installer's own parser with a sink that writes nothing, so "would it install" is the same answer an install gives.
+- **Tab** in a viewer shows the same file as hex, or as text (not in Q134).
+- **Maintenance** is the last row at the top of the card, and `m` anywhere in the App. It's the old Settings > Storage page behind a dialog.
+- **The Storage Warning** was only ever a Toast; "selecting it opens Storage Clean-up" (CONTEXT.md) was never built. It now reads "SD card over 80% full: see Storage".
+- **Console:** `cp`, `mv`, `mkdir` (Q138), and `rm` and `du` through the same code, so `rm` now takes folders and follows the rules; `ls` shows dates. Debug Builds: `sd fill <folder> <count>` makes test files.
+
+### Checks on the device (2026-10-06, v0.8.1-2 Debug Build)
+
+All in a scratch folder, `/f1test`, removed afterwards.
+
+| Check | Result |
+|---|---|
+| Host tests | 424 pass (411 before the viewers' models) |
+| Browsing | Folders first, sizes and dates, the three sorts; a 300-file and a 329-file folder show "first 256 of 300" and "of 329" |
+| New folder, rename, copy, cut and paste, delete | Each works on a file and on a folder; a copy next to its original is named `(2)`; a name in the way asks "Replace it?" |
+| A folder of 11 files, 8.4 MB, copied | 19.4 s, 435 KB/s, the bar moving; two Log lines queued meanwhile were written |
+| The same copy cancelled at 1.8 MB | "Cancelled: nothing was copied", and nothing was left behind |
+| Delete | 341 files in 9.7 s; the dialog had counted them first |
+| Read-only rules | `/irc`, `/gnss` (top-level folders), `/`, `/gemini/cache` and a folder made inside it, a folder into itself, a name with `:`; a Capture being recorded and the folder holding it; a folder under `/irc` while IRC runs. Each refused with its reason; the Capture could still be copied |
+| Text | A 1 MB log opens at its last line at once; top, pages, lines; a file without an extension that looks like text opens as text |
+| Hex | A 5 KB binary file; Tab from any other viewer |
+| `.pcap` | A LoRa Capture: 3 packets as the Scanner lists them, Enter shows the Meshtastic header and bytes |
+| `.gpx` | 400 points: start, 33 min 15 s, 4.68 km; Tab shows the text |
+| `.ota` | A signed file: version, "intact", "older than what's running", Enter asks to install (not confirmed). A tampered one: "image corrupted (hash mismatch)" |
+| Maintenance | The warning, then usage, Clean-up's categories and Erase (not run) |
+| Date with GNSS only | NTP pointed at an address that doesn't answer, restart: the Clock came from the Fix, and a folder made then is dated 2026-10-06 08:39. A Track from the day before, written the same way by v0.8.1, shows "-" |
+| Memory | IRC connected, the App open on 256 entries: 61 KB free (70 KB before opening). Lowest since boot 29.7 KB, during IRC's TLS handshake |
+| Stacks | `storage` 3.1 KB free of 6 KB at worst, `loopTask` 1.5 KB |
+
+**Not checked by hand:** how the keys feel on the device itself; everything above was driven through the Debug Console's `key` command and screenshots.
+
+**One slip during the checks:** a scripted key sequence ran in the wrong folder and renamed `/gemini/saved` to `saved2`, then copied it to the top of the card. Both were put right at once (renamed back, the copy deleted; 7 files, 53,798 bytes, as before).