Show the progress rate over the last 5 seconds, and where a phase waits after 10 seconds with no item done (closes #125)

The rate was the phase's average, so a burst after a long wait read as
over 1,000 files a second. It now covers the items completed over the
last 5 seconds, or since the line before off a terminal; the ETA still
comes from the average. Once no item has completed for 10 seconds, the
rate gives way to "stalled" and where the phase waits, as "stalled
disk/db": disk, db, out (stdout) or cpu, or two of them. A line too
wide for the terminal loses its bar first, then its rate or those
words, so the phase, progress, elapsed time and ETA stay whole. The
content phase's last partial batch is now written under a display of
its own. The tests set the display's clock by hand.

Deviation: the stall words hold no time and name where the phase waits, not what it does.
Judgement call: trees' group phase, which works in memory, says "cpu".

Model: opus-5-5

README.md

@@ -878,15 +878,17 @@ Additional requirements:
   terminal is. A line too wide for the terminal first loses its bar, which gives
   way to the spinner, then its rate, the words of a stalled phase, or what the
   phase is waiting for. The phase and its place, the progress, the elapsed time
-  and the ETA are kept whole. On an 80-column terminal, a stalled line at counts
-  and times like those of the stalled line in the example above keeps its words
-  whole in every phase; where the words and the ETA do not both fit, as at
-  millions of files and times in hours, the words give way. Only when those four
-  alone are too wide, as on a terminal narrower than about 70 columns hours into
-  a scan of millions of files, is the line cut short at the terminal's edge, so
-  the end of the ETA is lost first. A terminal made narrower while a phase runs
-  gets the same: the next draw erases the line within the new width and fits the
-  line to it, and the display goes on redrawing in place.
+  and the ETA are kept whole. On an 80-column terminal, at counts like those of
+  the stalled line in the example above, a stalled line keeps its words whenever
+  the elapsed time and the ETA are both in minutes, except in the content
+  phase's checks and reads. Their lines are the widest, and at most times in
+  minutes they lose the words. Where the words and the ETA do not both fit, as
+  at millions of files and times in hours, the words give way. Only when those
+  four alone are too wide, as on a terminal narrower than about 70 columns hours
+  into a scan of millions of files, is the line cut short at the terminal's
+  edge, so the end of the ETA is lost first. A terminal made narrower while a
+  phase runs gets the same: the next draw erases the line within the new width
+  and fits the line to it, and the display goes on redrawing in place.
 - When stderr is not a terminal (a pipe, a file, `/dev/null`), do not emit ANSI
   redraws: print the line the moment each phase starts, every 5 seconds while it
   runs (whether or not an item has completed, and never more often), and once

TODO.md

@@ -38,9 +38,11 @@
   `db`, `out` for stdout or `cpu`, or two of them for a phase that may wait on
   either, each phase giving its word where it is defined. A line too wide for
   the terminal loses its bar first, then its rate or those words, so the phase,
-  progress, elapsed time and ETA stay whole; on an 80-column terminal the words
-  fit beside them in an ordinary scan. The content phase's last partial batch is
-  now written under a display of its own (2026-10-16,
+  progress, elapsed time and ETA stay whole. On an 80-column terminal, at counts
+  like those of README's example, the content phase's checks and reads lose
+  those words at most times in minutes, and every other phase keeps them
+  whenever the elapsed time and the ETA are both in minutes. The content phase's
+  last partial batch is now written under a display of its own (2026-10-16,
   https://git.eeqj.de/sneak/sfdupes/issues/125)
 
 - new subcommand `info` prints the database's details on stdout, one per line as