Rewrite TODO.md sentence by sentence (closes #135)

TODO.md is the project's own task list, judged by the same rules as
README.md: short sentences, lists as bullets, nothing a newcomer reads
twice. Every completed step is kept with its date and its issue or
branch, and every fact the old entries recorded is kept too, in short
sentences. The 2026-07-22 policy-compliance checklist is folded into
the step that did the work, and the accepted divergence from the
layout policy gets a section of its own. Workflow, Status and Next
Step keep their rules unchanged.

Model: fable-5-1

TODO.md

@@ -156,12 +156,12 @@ are known.
     the default excludes only, and `scan --help` lists them (2026-10-17,
     https://git.eeqj.de/sneak/sfdupes/issues/124)
 
-- The rate a progress display shows covers the items completed over the last 5
-  seconds. When stderr is not a terminal, it covers the items since the line
-  before. It falls to 0 while nothing completes. A burst after a wait no longer
-  reads as a steady rate of over 1,000 files a second. The time remaining still
-  comes from the phase's average. Once no item has completed for 10 seconds, the
-  word `stalled` and where the phase waits take the rate's place, as
+- A progress display's rate covers the items completed over the last 5 seconds.
+  When stderr is not a terminal, it covers the items since the line before. It
+  falls to 0 while nothing completes. A burst after a wait no longer reads as a
+  steady rate of over 1,000 files a second. The time remaining still comes from
+  the phase's average. Once no item has completed for 10 seconds, the line shows
+  `stalled` and where the phase waits in place of the rate, as
   `stalled disk/db`. The places are:
     - `disk`;
     - `db`;
@@ -176,12 +176,12 @@ are known.
     - the elapsed time;
     - the ETA, the time remaining.
 
-    On an 80-column terminal, at counts like those of README's example, the
-    content phase's displays for its checks and its reads lost those words. That
-    happened for most elapsed times and ETAs in minutes. Every other phase kept
-    them whenever the elapsed time and the ETA were both in minutes. The content
-    phase writes its last partial batch, the records not yet written, under a
-    display of its own (2026-10-16,
+    The content phase had one display for its checks and one for its reads. Both
+    lost those words on an 80-column terminal, at counts like those of README's
+    example. That happened for most elapsed times and ETAs in minutes. Every
+    other phase kept them whenever the elapsed time and the ETA were both in
+    minutes. The content phase writes its last partial batch, the records not
+    yet 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
@@ -285,8 +285,8 @@ are known.
 - With `-x`, an operand under another operand is no longer dropped when a
   directory between the two, the inner one included, is on a different
   filesystem than the outer one. The inner operand is then walked on its own.
-  For a regular-file operand the directories checked start at its directory. The
-  records of files gone from below it are deleted (2026-10-14,
+  For a regular-file operand the check starts at its directory. The records of
+  files gone from below it are deleted (2026-10-14,
   https://git.eeqj.de/sneak/sfdupes/issues/106)
 
 - With `-x`, `scan` keeps the records below a directory on another filesystem
@@ -294,8 +294,8 @@ are known.
   census (2026-10-14, https://git.eeqj.de/sneak/sfdupes/issues/99)
 
 - The hash and content phases open each file without blocking and check that it
-  is still a regular file. A file replaced by a FIFO or device node after it was
-  statted is warned about and skipped instead of hanging the scan (2026-10-14,
+  is still a regular file. A file that is now a FIFO or device node is warned
+  about and skipped instead of hanging the scan (2026-10-14,
   https://git.eeqj.de/sneak/sfdupes/issues/100)
 
 - The scan lock file is named from the database's path with symlinks resolved,
@@ -449,8 +449,8 @@ are known.
   phase. The content phase ran after the update phase. It read a file for
   `content` only when its size, `head` and `tail` matched another record's, from
   this scan or an earlier one. `content` was the whole file below 50 MiB, and
-  gigabyte-spaced 1 MiB samples at or above. A file gone or changed since its
-  record was written was never read. `report` and `trees` left out any record
+  gigabyte-spaced 1 MiB samples at or above. It never read a file gone or
+  changed since its record was written. `report` and `trees` left out any record
   without a `content` hash. The `content` column is part of the version 1
   schema. Superseded by https://git.eeqj.de/sneak/sfdupes/issues/132
   (2026-09-22, branch `next`, https://git.eeqj.de/sneak/sfdupes/issues/61)
@@ -483,9 +483,9 @@ are known.
 - The Docker build stage's prerequisites were installed by running
   `script/bootstrap` instead of `apk add --no-cache make` inline.
   `script/verify-linter-pin` failed the build unless the linter copied from the
-  lint stage was the version `script/bootstrap` pinned. Builds then took up to
-  5m14s from an empty cache, mostly in a `chown -R` of the module cache, filed
-  as https://git.eeqj.de/sneak/sfdupes/issues/43. Since
+  lint stage was the version that `script/bootstrap` pinned. Builds then took up
+  to 5m14s from an empty cache, mostly in a `chown -R` of the module cache,
+  filed as https://git.eeqj.de/sneak/sfdupes/issues/43. Since
   https://git.eeqj.de/sneak/sfdupes/issues/95 the build stage installs `git` and
   `make` with `apk add --no-cache` and only compiles. The `lint` and `test`
   phases are the gates (2026-08-09, branch `dockerfile-bootstrap`,
@@ -545,17 +545,18 @@ are known.
     - the whole database layer.
 
     The walk pool gets the same treatment, plus a `ctx.Err()` guard after the
-    walk. A cancelled walk yields a partial size census, and every file it never
-    reached looks vanished to the update phase. That phase's own `BeginTx` also
-    fails on the cancelled context before deleting anything. The guard is still
-    the barrier once an interrupted scan may commit what it has. Tests drive
-    `run(scan)` against a database whose insert trigger aborts. They assert that
-    the scan fails instead of hanging, and that the goroutine count returns to
-    its pre-scan baseline. Other tests cancel a scan part-way through the walk,
-    deterministically, by counting the scan's own checks of `ctx.Done()`. They
-    assert that it stops at the guard with every record intact. It then holds a
-    partial size census and a still-populated record index. Direct tests cover
-    the remaining cancellation branches of both pools. They test:
+    walk. A cancelled walk yields a partial size census, and every file that it
+    never reached looks vanished to the update phase. That phase's own `BeginTx`
+    also fails on the cancelled context before deleting anything. The guard is
+    still the barrier once an interrupted scan may commit what it has. Tests
+    drive `run(scan)` against a database whose insert trigger aborts. They
+    assert that the scan fails instead of hanging, and that the goroutine count
+    returns to its pre-scan baseline. Other tests cancel a scan part-way through
+    the walk, deterministically, by counting the scan's own checks of
+    `ctx.Done()`. They assert that it stops at the guard with every record
+    intact. It then holds a partial size census and a still-populated record
+    index. Direct tests cover the remaining cancellation branches of both pools.
+    They test:
     - `sendEvent`;
     - the walk workers;
     - `dispatchDirs`;
@@ -672,8 +673,8 @@ are known.
     - `LICENSE` and the README License section. MIT was assumed from house
       convention, for the owner to confirm;
     - `REPO_POLICIES.md` in the repo root;
-    - the canonical `.golangci.yml`, with the 150 findings it raised fixed, so
-      that `make lint` is clean;
+    - the canonical `.golangci.yml`, with its 150 findings fixed, so that
+      `make lint` is clean;
     - the `Makefile` targets the policy requires:
         - `test` and `lint`;
         - `fmt` and `fmt-check`;