docs(changelog): document the v0.69.2 drift

[max-sixty]

Eleven commits landed on main while #3590 sat in CI, so they ship in v0.69.2 with no changelog entry. Most are user-facing, and three are data-loss fixes — exactly the drift the release skill's step-12 check exists to catch. The tag is held until this lands.

Entries added, most-impactful first:

• fix(shell): don't delete user lines that only quote the init command #3589 — two ways shell integration deleted user data on a substring guess: an rc line that only quotes the init command, and a user's own conf.d/wt.fish deleted outright by install's legacy cleanup. Plus forge detection moving from host.contains("github") to label-wise matching.
• fix(shell): rewrite rc files atomically on uninstall #3585 + fix(config): route every user-file write through one atomic writer #3591 — truncate-in-place rc writes replaced by write-temp-then-rename, then generalized to every user-file write.
• docs(step): render wt step rebase & wt step push on the docs site #3578 — despite its docs(step): subject this carries three behavior fixes, including wt step push succeeding mid-rebase and moving the target branch onto a half-replayed history.
• fix(step): gate every staging path on an unmerged index #3588 + fix(merge): refuse unresolved conflicts in merge's own name #3587 — conflict markers can no longer reach a commit via wt step relocate --commit, and wt merge refuses in its own name.
• fix(plugin): scope OpenCode marker commands to the plugin's directory #3554 — OpenCode marker writes could land in another session's worktree (thanks @4i3n6, who both reported and fixed it).

Not documented, per convention: #3574 (doc comments only, no runtime or docs-site surface) and the three dependency bumps.

Also corrects .github/CLAUDE.md, which lists three required status checks; there are four — fast-checks is required too, confirmed against the branch-protection API.

Entries verified against the diffs by subagent. Two corrections came back and are folded in: the #3589 entry originally promised "two of them deleted" and described only one, and the #3578 entry mis-quoted the success line as ✓ Pushed to main when it carries a commit count.

This was written by Claude Code on behalf of max