Skip removed paths silently and fix the progress line (closes #133)

A path removed while the scan runs gets no warning and no skipped
count, in the walk or the hash phase. If the first of several hard
links is gone, the next is read. Other errors are still warned about.

On a terminal every display is the library's spinner, then the line. A
phase with an exact total ends the padded line with its percent and a
bar at a fixed column, drawn by sfdupes, as the library shows no
spinner beside its own bar. A too-wide line loses its rate first.

The time remaining is labelled remain, not eta.

Judgement call: an operand removed mid-scan is skipped silently too.
Deviation: README's stalled-line example keeps its words on 100
columns, not 80.

Model: opus-5-5

TODO.md

@@ -29,6 +29,16 @@
 
 # Completed Steps
 
+- a file or directory removed while the scan runs is not an error, in the walk
+  or in the hash phase. The scan prints no line for it and does not count it as
+  skipped. When the first of several hard links to a file is gone, the hash
+  phase reads the next one instead. On a terminal every progress display starts
+  with the spinner, the hash phase's included. A phase with an exact total ends
+  its line with its percent and a 10-column bar at the terminal's right edge,
+  which no longer moves as the line's length changes. A line too wide for the
+  terminal now loses its rate before its bar. The time remaining is labelled
+  `remain`, not `eta` (2026-10-26, https://git.eeqj.de/sneak/sfdupes/issues/133)
+
 - the `head`, `tail` and `content` columns are BLOBs, each holding the raw 32
   bytes of a SHA-256, half the size of the hex text they held. The hashes stay
   raw from the hash phase through the database to `report` and `trees`. Reading