fix: preserve lazy snapshots for conflicted jj revisions

Conflicted revisions read every file through jj file show, which returns
empty output for symlinks and causes repository-wide subprocess fanout.
Keep ordinary Git blob sources and immutable identities; render only
selected conflicted paths through jj.

Verified all 905 tests and the original local bookmark comparison with
25 correct paths in 0.522s, plus actual terminal conflict viewing.
Strict Clippy is blocked by existing diagnostics outside this change.

docs/development.md

@@ -56,6 +56,8 @@ Clipboard checks use isolated providers rather than reading or overwriting the d
 
 Diff checks cover staged category/filter navigation, stale request cancellation, row alignment, read-only buffer isolation, and rendered panes. Repository integration fixtures exercise Git and Git-backed jj, advertised but unfetched remote branches/bookmarks/tags, imported historical commit/change IDs, conflicts, unusual paths, binary/mode/link/submodule changes, and unchanged active metadata. Remote fixtures are local bare copies; they never push. Git fixture identities and commit dates are fixed.
 
+Conflicted-revision regressions preserve unchanged symlinks, defer oversized unselected blobs until file selection, compare selected conflict text with jj's projection, and exclude unchanged conflicts when comparing later revisions. Live terminal smoke covers local bookmark selection and opening an actual conflicted file without changing the checkout.
+
 Repository gutter checks cover LF/CRLF normalization, additions/replacements/deletion anchors, staged/disk/unsaved Git text, unborn and missing named files, ignored/unsupported paths, read-only colocated/non-colocated jj queries, stale results and per-buffer isolation, plus rendered modes, colors, current-line precedence, wrap/scroll and narrow/split geometry. Live PTY smoke verifies all four modes, edit/undo refresh, external Git HEAD changes, and jj parent changes without editor restart.
 
 Normal-picker checks cover staged/disk/unsaved status, binary and mode changes, exact and ambiguous renames, deleted paths, unborn repositories, aliases and unusual filenames, ignores and safe roots, linked worktrees, and read-only colocated/non-colocated/conflicted jj parents. Catalog/render checks retain unchanged rows, query/selection/expansion and Tree/List navigation, clear stale metadata, restore recreated files, and sanitize rename labels. Live PTY smoke checks A/M/D/R colors in floating and docked pickers with the line gutter disabled, Git HEAD/jj parent refresh, and unchanged jj operation state during polling.

docs/editing.md

@@ -394,6 +394,8 @@ Missing or unprepared historical metadata is reported when selecting the affecte
 
 Comparison discovery builds the changed-path/status catalog first. File text, notices, and hunks load asynchronously when a file is selected and remain cached for that comparison. Failed file loads can be retried by selecting the file again; cancelled or superseded results cannot replace the current selection. Working-checkout comparisons still capture working bytes and the historical content needed to identify changes, preserving the frozen Before snapshot and unsaved After buffers.
 
+Conflicted jj revisions also discover files without reading every blob. Ordinary files and symbolic links retain their Git contents; selected conflicted files show jj's rendered conflict projection. Unchanged links and jj's internal merge-tree metadata do not appear as changes. Viewing a conflict does not resolve it or modify the revision.
+
 **Working checkout After follows forward checkouts automatically**, checked asynchronously once per second, including inactive tabs. A descendant jj change or Git HEAD rebuilds the changed-file catalog and captures current working bytes plus eligible unsaved buffers, while keeping the original Before frozen. jj tracking uses change IDs, so snapshot/description rewrites of the same change do not advance the endpoint or prevent following its later descendants. Same, backward, and unrelated checkouts do not rebuild the catalog; live-buffer editing and external reload still work normally. Historical After never follows. Set `config.diff_follow_working_copy = false` to disable following.
 
 **Pinned After editability tracks the checkout without moving either endpoint**, checked asynchronously once per second, including inactive tabs and when `config.diff_follow_working_copy = false`. Git matches the selected commit to HEAD; jj matches its change ID so snapshot/description rewrites of the same change remain editable. A matching After uses the shared live buffer. Switching away restores the original read-only After snapshot; switching back reuses the live buffer's unsaved edits and undo history. A failed checkout check revokes pinned After editing until a successful check restores eligibility.