docs: soften manual claim that delegates 'act as backups and replicas'

[sanity]

Problem

The user-facing manual at https://freenet.org/build/manual/components/delegates/ states:

Delegates can also synchronize with identical delegate instances running on other devices the user controls. With an appropriate shared secret, they communicate securely via Freenet and act as backups and replicas of each other.

This is aspirational, not implemented. The vault-delegate primitive that would deliver multi-device sync is tracked in #3050 (still in design). PR #4034 (per-secret snapshot history) added a local durability slice but does not provide cross-device sync.

Users reading the current wording reasonably assume their delegate data is safe across device loss. It isn't.

Proposal

Soften the wording to reflect actual current behavior, and either link to #3050 as the tracking issue or remove the aspirational sentence entirely. The local snapshot-on-write history added in #4034 is worth mentioning as the existing durability story.

Suggested text (rough draft):

Delegates store their state encrypted on the local device. Recent prior values are kept as snapshots so accidental overwrites can be recovered. Cross-device synchronization is not yet implemented — see issue #3050 for the planned vault-delegate primitive.

Note for resolver

This change lives in the web/ repo (Hugo source for freenet.org), not in freenet-core. The issue is filed here for visibility because the inaccuracy is about a freenet-core feature.

[AI-assisted - Claude]

[github-actions]

🤖 Auto-labeled

Applied labels:

• T-docs (98% confidence)
• E-easy (95% confidence)
• A-documentation (97% confidence)

Reasoning: The report asks to soften and correct wording in the user-facing manual and points to the Hugo source in the web/ repo. This is a documentation change (T-docs) and is small/straightforward to implement (E-easy). The primary impacted area is documentation (A-documentation). No bug/feature priority label is needed because this is not code-level functional work.

Previous labels: P-low, A-contracts

If these labels are incorrect, please update them. This helps improve the auto-labeling system.