Shell: only its own replies, Apps by their names, and rm as Unix has it (#67)

The Shell shows the replies to its own commands and nothing else. The
console knows who each line is printed for (Console::As, Console::origin):
a command run from the Shell prints as the Shell's, and what answers it
later from another task carries that along (ls, tasks, du, cp, update
check, sd list, screenshot, gemini get). Ctrl+b shows everything instead.
This replaces the ten-second window, which was a guess.

An App's name with a capital opens it (Notes, Irc, Wifi, Gnss, Gemini, Lora,
Storage, Shell, System, Settings), from the Shell and from the consoles.

rm needs -r for a folder, here and over the consoles. In the Shell a file,
or a folder with something in it, is asked about unless -f; an empty folder
with -r goes without a word.

The Shell now hands its line to the main loop to run: run from inside the
key handler, rm on a folder overflowed the loop's stack and crashed the
device. `info` says which App is in front.

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

docs/milestones/S1.md

@@ -147,22 +147,34 @@ The console's commands could only be typed on a PC: over USB, or over Wi-Fi with
 |---|---|
 | Q204 | **An App, "Shell", in the Launcher**, in every firmware: its commands already work over USB for anyone holding the device. |
 | Q205 | **Trusted like USB serial**, not like the network: `debug on` and `debug token` work from it, as they do in Settings. The token is never shown. |
-| Q206 | **It shows what the console prints while it is open**, replies and background alike, without the free-heap line every ten seconds. **Ctrl+b hides the background:** then only what is printed in the ten seconds after a command is kept. A reply can't be told from other output any better: `ls` and `tasks` answer later, from other tasks. |
+| Q206 | *Revised the same day, after trying it.* **It shows the replies to its own commands, and only those.** The console knows who each line is printed for (`Console::Origin`): a command run from the Shell prints as the Shell's, and so does what answers it later from another task, which notes who asked and takes it back when it prints (`ls`, `tasks`, `du`, `cp`, `update check`, `sd list`, `screenshot`, `gemini get`). What USB or the Debug Console asked for, and the system's own lines, are not the Shell's. **Ctrl+b shows everything** instead. The first version kept whatever was printed in the ten seconds after a command, which was a guess, and a noisy one. |
 | Q207 | **Nothing while it's closed.** Open, a 4 KB ring of the console's and up to 4 KB of lines; both go when the App is left, with the list of commands for Tab. |
 | Q208 | Enter runs the line; Fn with up and down recalls the last 16; Alt with up and down scrolls back; **Tab completes the command's first word** from the firmware's `help` text. Paths aren't completed. |
-| Q209 | **`rm` asks first, `rm -f` doesn't** (in the Shell only: over the consoles, scripts delete as before). **`screenshot [seconds]`** saves the screen as a PNG in `/screenshots`, now or after a pause, since from the Shell "now" is the Shell. `get`, `put`, `coredump get` and `reset` answer `Debug Console only`. |
+| Q209 | *Revised the same day.* **`rm` is Unix's, with a question.** A folder needs `-r`, here and over the consoles (where `rm <folder>` used to remove it with what was in it). In the Shell, a file, or a folder with something in it, is asked about unless `-f` (`-rf`, `-r -f`); an empty folder with `-r` goes without a word; what `rm` would refuse anyway, it refuses itself. Over the consoles nothing is asked: scripts delete as before. **`screenshot [seconds]`** saves the screen as a PNG in `/screenshots`, now or after a pause, since from the Shell "now" is the Shell. `get`, `put`, `coredump get` and `reset` answer `Debug Console only`. |
 | Q210 | Commands are echoed as `> command` into the console, so a session reads the same from afar. **A token being set is not echoed.** |
 | Q211 | **Not in Safe Mode**, which starts no Apps: issue #77. |
 | Q212 | Its keys are a table in `app_keys.h`, so the help panel and the website have them; a page in the user guide. |
+| Q213 | *Added the same day.* **An App's name with a capital opens it:** `Irc`, `Wifi`, `Gnss`, `Gemini`, `Lora`, `Storage`, `Notes`, `Shell`, `System`, `Settings` (the App's id, up to its first dash). From the Shell, without going back to the Launcher, and from the consoles too. The capital says "an App": every command of the firmware is in small letters. Tab completes them. |
 
 ### As built
 
-- **`ShellApp`** (`src/apps/shell_app.cpp`), with its model host-tested in `lib/apps_model/src/shell_log.h`: lines arriving in pieces, the two filters, the 4 KB limit, the command words out of the `help` text, and Tab (7 tests).
-- **The console has a second ring** (`Console::openShellRing`), filled like the Debug Console's and independent of it.
+- **`ShellApp`** (`src/apps/shell_app.cpp`), with its model host-tested in `lib/apps_model/src/shell_log.h`: lines arriving in pieces, the 4 KB limit, the command words out of the `help` text (Apps' names included), and Tab.
+- **Who a line is for:** `Console::As` marks the calling task as printing for the Shell while it lives, and `Console::origin()` lets a command that answers later carry that to wherever it prints. The console has a second ring for the Shell, which gets the lines marked so, or everything.
+- **The Shell hands its lines to the main loop**, which runs them like the consoles' commands. See below for why.
+- **`info` says which App is in front** (`app: Shell`): so that a hand driving the device from afar can look before it types.
 - **`screenshot`** writes the PNG a row at a time with no buffer: 8-bit indexed colour, the 256 colours of RGB332 as the palette, the pixels in one stored deflate block (`lib/files/src/png_rgb332.h`, 4 tests). 33,383 bytes for the 240 x 135 screen. A Toast says so once it is on the card, so the Toast is never in the picture.
 - **The `help` text lost its shorthand** (`update check | list | status` is written out), since Tab reads its first words from there.
-- **Cost:** 12 KB of flash, 16 bytes of static RAM. Open: 7 KB of heap (107.6 KB free before, 100.7 with it open, 106.1 after leaving).
+- **Cost:** 16 KB of flash, 56 bytes of static RAM. Open: 7 KB of heap (107.6 KB free before, 100.7 with it open, 106.1 after leaving).
 
+### What went wrong while building it
+
+**The device crashed, and the test sent a message to an IRC channel.** The first version ran a command from inside the key handler. Driven from the Debug Console, that is: the main loop, a remote command, `key select`, the App manager, the Shell, `runCommand` a second time, the file command, and `printf` under all of it. The main loop has under 2 KB of stack to spare; `rm` on a folder went past it. The crash report decoded to exactly that chain.
+
+The device restarted into the Launcher, and the test script, which did not look, went on typing. Its next Enter opened IRC, which connected, and a few lines later it typed "No" into a channel and pressed Enter. One word, sent to real people, that can't be taken back.
+
+Two changes came of it. The Shell now **queues** its line and the main loop runs it, at the same stack depth as a console's command. And `info` reports the App in front, which the test script now checks before every line it types.
+
+### Checks on the device (2026-10-07, driven over the Debug Console with `key`)
 ### Checks on the device (2026-10-07, driven over the Debug Console with `key`)
 
 | Check | Result |
@@ -171,7 +183,12 @@ The console's commands could only be typed on a PC: over USB, or over Wi-Fi with
 | Tab on `in` | `info  install` is shown and the line stays; on `u` it becomes `update `; on `l`, `log  ls  lora  loop` |
 | Up | The line before comes back |
 | `screenshot` | `/screenshots/20261007-104357.png`, 33,383 bytes. Fetched and decoded on the PC: 240 x 135, indexed, every chunk's CRC right, the pixels the Shell's screen |
-| `rm /shelltest` | Asks. Cancel leaves the folder; Delete removes it. `rm -f` removes without asking |
+| Output | With a Debug Console client connecting and disconnecting for every key, the Shell shows the commands and their replies and nothing else: `info`, `ls /` (answered by the storage task), `tasks` (answered a second later) |
+| `rm` on a folder, without `-r` | Refused, the folder stays |
+| `rm -r` on an empty folder | Removed, no question |
+| `rm -r` on a folder with files | Asks; Cancel leaves it. `rm -rf` removes it without asking |
+| `rm` on a file | Asks; Delete removes it |
+| `No`, Tab, Enter | Completes to `Notes ` and opens Notes. `Shell` from the Debug Console opens the Shell |
 | `screenshot 4`, then Home | The picture, taken four seconds later, is of the Launcher: the pause works, and the Toast isn't in it |
 | `quit` | Back to the Launcher, and the memory comes back |
 | The help panel in the Shell | Its keys, then the ones that work everywhere |