Entry form: audit block, every field selectable, sideways scrolling

[oetiker]

Started as "show the entry's timestamps"; the review of that surfaced a deeper
problem — values you cannot reach are values you cannot read — which the rest of
the branch fixes.

Audit block

Below the form, separated by a blank row, the entry's server-maintained
createTimestamp, creatorsName, modifyTimestamp and modifiersName,
labelled created / created by / modified / modified by:

                  created  2026-07-28 11:34:02
               created by  cn=admin,dc=example,dc=org
                 modified  2026-07-28 12:01:09
              modified by  cn=admin,dc=example,dc=org

Timestamps render in local time (the offset is captured once at the top of
main, because time refuses to read it in a multi-threaded process). Entry
reads request these operational attributes explicitly — * is user attributes
only, which is why they were absent. The save path already re-reads the entry, so
modified refreshes itself.

The trap this had to avoid: EditForm::to_edit_entry feeds validate(), so
had these attributes leaked in, every save would have failed with "attribute
not allowed by objectClass" — and the orphan sweep in sync_schema_fields would
have emitted a Delete against a server-maintained attribute on any objectClass
change. Both are covered by tests. Classification is by attribute name
(form_model::is_meta_attr), not a per-field flag: these are operational, so
they can never be in an objectClass's MUST∪MAY, and one predicate cannot desync
the way a flag threaded through 53 struct literals could.

Every field is selectable

Read-only cells were disabled, which focus skips entirely — so a value wider
than its cell could never be scrolled to its end, selected, or copied. They are
now read_only (tvision-rs 0.15.0, developed for this and upstreamed in
oetiker/tvision-rs#22): reachable, scrollable, copyable, refusing only edits.

An edit attempt raises READ_ONLY_REJECTED; the pane answers with a dialog that
names the attribute and the reason — server-maintained, schema
NO-USER-MODIFICATION, read-only session, orphaned, binary, boolean, or declared
read-only in config. PageUp/PageDown still page the viewport, so long forms
stay quick to cross.

Three existing tests encoded "read-only means unreachable". They were rewritten
to the guarantee that survived rather than deleted: the head/tail tests now
assert those rows can be reached and revealed (and that a passive re-anchor
does not yank the reveal back), and the clamp test keeps its real subject — no
wrap at either end.

Sideways scrolling

The list and launch blocks painted with put_str, which cuts silently at the
right edge, so a long member DN was unreadable even with focus. Both now carry a
horizontal offset with ◄/► marking hidden text: ←/→ and Home/End
move a read-only block, while the inline editor follows its caret.

member*  - cn=user01,ou=users,dc=example,d►     fresh
member* ◄=user01,ou=users,dc=example,dc=org     after End

Text cells use the new ValuePosition::Start, so a DN shows its head rather than
…,dc=example,dc=org.

Also

• A truncated dn title now ends in …, so a cut DN is distinguishable from a
  short one. (It already cut at the end — only the marker was missing; the …
  that looked like front-truncation was Create mode's RDN placeholder.)
• Meta labels are the bare hint, because modifiersName (modified by) would be
  the longest label in the form and the label column is sized to the longest
  label of all rows — it squeezed every value cell on a narrow pane.

Verification

make check green (fmt, clippy -D warnings, all tests); mdBook builds. Driven
live against the podman demo server throughout: the block renders with real
values, local time matches the server's Z value, an edit saves with only the
edited attribute in the LDIF and the block refreshes, read-only fields scroll and
refuse with the dialog, and member lists scroll sideways.

Design docs: docs/superpowers/specs/2026-07-28-entry-meta-block-design.md and
…-every-field-selectable-design.md.

🤖 Generated with Claude Code