docs(GOAL): correct four stale status statements for merged capabilities

[xiaocui-big]

Summary

• Closes docs(GOAL): four status statements list capabilities that are now merged and reachable #179.

Update GOAL.md §5 rows and §6 checkboxes to reflect what main already ships, so the gap list no longer understates the current state.

§5 changes

维度	变更
跨设备恢复	正文加入 merge_conservative 已实现；判断从"尚无 merge、增量同步和断点上传"改为"尚无增量同步和断点上传"，把已合并的 merge 和未实现的增量同步/断点上传分开
人类可视化	覆盖范围加入 correction/supersede；判断从"尚缺 correction/supersede 与完整审计历史"改为"尚缺完整审计历史"
数据可移植性	正文加入支持 fresh 与 merge_conservative 两种导入模式；判断从"MVP 对齐：当前服务只支持 fresh restore"改为"MVP 对齐"

§6 changes

• P1: 把原来的单条拆成 [x] merge_conservative 和 [ ] 增量包、断点上传。
• P2: 把原来的单条拆成 [x] correction/supersede、导入历史、权限管理 和 [ ] 完整审计历史。

Evidence

每条更正都有对应的 main 代码路径：

• merge_conservative — server/internal/workspacetransfer/merge.go, server/internal/db/migrations/0023_workspace_import_merge.sql (PR feat(transfer): implement merge_conservative workspace restore #98)
• correction/supersede — server/internal/db/migrations/0022_memory_relations.sql, server/internal/memory/relation.go (PRs feat(memory): add immutable correction, supersede, and occurrence relations #90, feat(web): expose memory correction and supersede relations #95)
• 导入历史 — server/internal/workspacetransfer/history.go (PR feat(transfer): add import history ledger endpoint and TransferPage view #102)
• 权限管理界面 — web/src/pages/PermissionsPage.tsx (PR feat(web): add admin permissions management page for tokens and recall grants #100)

Test plan

• 确认 §5 三行的正文与判断列不再把已合并能力列为缺失。
• 确认 §6 P1 和 P2 的 checkbox 只保留真正未完成的部分为 unchecked。
• 确认未触及的行（统一存储、Agent 入口、跨 Agent 记忆、标准任务交接、Claude Code/Codex 迁移、自然语言搜图）未被改动。

[waterbro-8]

Closing as superseded by #181

This is the same change as #181, which is already approved and verify-reviewed.
Both touch only GOAL.md and correct the same four stale status statements
(#179); the two heads differ by a single clause of phrasing, with identical
meaning:

-| **部分对齐：merge 已完成，尚无增量同步和断点上传** |
+| **部分对齐：尚无增量同步和断点上传** |

I am keeping #181 rather than this one, for reasons that are about evidence
state rather than preference:

• docs(goal): correct four stale status statements for merged capabilities #181 carries a verification approval that re-derived all four corrected
  statements against main at 3c13f04, including checking that the
  statements it leaves unchecked are genuinely still unimplemented — the point
  of this file is that it does not overstate, so the negative half matters as
  much as the positive half.
• docs(goal): correct four stale status statements for merged capabilities #181's wording keeps the explicit "merge 已完成" acknowledgement, which is
  clearer about which part is done. This PR's shorter phrasing is not wrong,
  but it is less informative about what merge_conservative covers.
• docs(goal): correct four stale status statements for merged capabilities #181's head is on the main branch's own history and its four workflow runs
  are green; this PR's head has no check-runs reported at all.

No action is needed from you. Thank you for writing the correction — the four
statements were genuinely stale, and this PR reaching the same conclusion
independently is useful confirmation that the fix is right.

Closes nothing; #179 stays open until #181 merges.