New-install privacy defaults, and expired bans purged daily

Personal-data catalog spec, defaults D2, D3, D4, D6 and D7 (settled
2026-09-28, new installs only):

- D2: automatic IP bans expire after 30 days instead of never; D3:
  spam training samples, whole messages, are kept 90 days instead of
  180; D4: Pyzor, which sends a digest of each message's text to a
  public server, is off; D6: delivery history is kept 14 days instead
  of 30. Written on the first boot of a new install only -- one with no
  roles yet, the same test the built-in roles use -- by reading each
  singleton, setting these fields and writing it back whole. A server
  with roles keeps its settings, saved or default.
- D7: a webhook created from now on starts with the include policy and
  no events, so it sends nothing until events are chosen (Rust default
  and schema default, marked). The registry stores every field, so
  existing webhooks keep their policy.
- Expired bans are also removed by the daily data clean-up. They
  already stopped blocking and were deleted when settings next loaded;
  a server that seldom reloads kept them.

D1 (log retention) and D5 (the hashed-address blocklist off) are held,
and the spec says why: x:TracerLog is stored inside x:Bootstrap with a
field after it, so adding one changes that object's stored format; and
the spam-rules loader D5 touches is being reworked by the v0.16.24
import. The spec also corrects finding 3: expired bans were deleted on
settings load; bans were permanent only because no period is set.

Tested: unit tests for the new-install values and that everything else
in each singleton stays; the system suite, whose security test now
purges an expired ban and checks its record is gone; the telemetry
test; common's unit tests; fork checks.

docs/spec/features/personal-data-catalog.md

@@ -151,7 +151,7 @@ These live in inbuxa's own key space (`SUBSPACE_INBUXA`) unless noted.
 | OAuth codes and tokens | credential | holder | `x:OidcProvider.*Expiry` | tokens are sealed and stateless (not stored); codes in the in-memory store with TTL | in-memory store | tenant | `http/src/auth/oauth/auth.rs`, `token.rs` | codes 10 min |
 | Rate-limit state | network, identifier (login names) | holder, correspondent | `x:Http.rateLimit*`, `x:Imap.maxRequestRate`, `x:Security.*BanRate` | the rate's period | in-memory store | server | `common/src/auth/rate_limit.rs`, `network/security.rs` | on |
 | Greylist | identifier (sender/recipient pairs, plain) | correspondent, holder | `x:SpamSettings.greylistFor` | that period | in-memory store | server | `smtp/src/inbound/rcpt.rs` | **off** |
-| Automatic IP bans (`x:BlockedIp`) | network | correspondent, holder | `x:Security.authBanRate`, `abuseBanRate`, `loiterBanRate`, `scanBanRate` (on); `*BanPeriod` (**no default**) | **unbounded: a ban with no period never expires, and no purge of expired bans was found**; each ban is also an audit record | data store (registry) | server | `common/src/network/security.rs` `block_ip` | **collected, permanent** |
+| Automatic IP bans (`x:BlockedIp`) | network | correspondent, holder | `x:Security.authBanRate`, `abuseBanRate`, `loiterBanRate`, `scanBanRate` (on); `*BanPeriod` (**no default**) | **unbounded: a ban with no period never expires**; an expired ban's record goes when settings next load; each ban is also an audit record | data store (registry) | server | `common/src/network/security.rs` `block_ip` | **collected, permanent** |
 | Allowed IPs | network | administrator's choice | manual; `expiresAt` | optional | data store | server | registry | none |
 
 ### 2.6 Spam filter and AI
@@ -197,8 +197,10 @@ not a judgment; what to do about each is John's call.
 2. **Log files are never deleted.** Daily rotation opens a new file; nothing
    removes old ones, and no logrotate configuration ships. At the default
    level every in-session line carries the client IP.
-3. **Automatic IP bans are permanent.** No `*BanPeriod` has a default, and no
-   purge of expired `x:BlockedIp` records was found.
+3. **Automatic IP bans are permanent.** No `*BanPeriod` has a default, so a
+   ban never expires. (Corrected 2026-09-28: a ban that does expire stops
+   blocking, and its record is deleted when settings are next loaded, in
+   `BlockedIps::parse`; the investigation missed that path.)
 4. **Some records outlive the account.** Deleting an account doesn't clear
    inbuxa's own key space: legacy-protocol last use, account locks, masked
    address records and audit records stay (audit records by design).
@@ -394,6 +396,17 @@ default; fails on a stale entry.
 Phase 3; existing servers keep their settings. D7 is also covered by the bug
 fix for finding 1 (Settled 6).
 
+**As built (2026-09-28).** D2, D3, D4, D6 are written on first boot of a new
+install only (no roles yet), each singleton read and written back whole
+(`manager/defaults.rs`, `new_install_privacy_defaults`); expired bans are
+also purged daily (`purge_expired_blocked_ips`). D7 changes the default for
+webhooks created from now on; stored webhooks keep theirs (the registry
+stores every field). **Held:** D1, because `x:TracerLog` is also stored
+inside `x:Bootstrap` with fields after it, so adding a field changes that
+object's stored format; a fork-owned setting is proposed instead, for John
+to decide. D5, because the spam-rules loader it touches is being reworked
+by the v0.16.24 import.
+
 | # | Change | Trade-off |
 |---|---|---|
 | D1 | A **log retention** setting on `x:TracerLog` (delete rotated files older than N days), default 30 days for new installs | Needs code (a new field, so a schema edit); older logs gone for troubleshooting; operators wanting longer set it |