docs: unwrap hand-wrapped prose repo-wide

docs/reference/files-and-directories.md

@@ -1,39 +1,16 @@
 # Files and directories
 
-Every path nxdns reads or writes, and the mode it is created with. Source of
-truth: `src/cli.zig` (`DataDir`), `src/storage/querylog_schema.zig` (the
-preserved query-log databases), `src/filter/manager.zig` (the blocklist
-snapshots), `src/platform/logging.zig` (the log file).
+Every path nxdns reads or writes, and the mode it is created with. Source of truth: `src/cli.zig` (`DataDir`), `src/storage/querylog_schema.zig` (the preserved query-log databases), `src/filter/manager.zig` (the blocklist snapshots), `src/platform/logging.zig` (the log file).
 
 ## The data directory
 
-Default `/var/lib/nxdns`, overridable with `--data-dir DIR`. `nxdns run` and
-`nxdns import` create it and its parents at mode 0700 when it is missing;
-`nxdns check` and `nxdns export` do not create it. `export` fails if it is not
-there. `check` opens it only when no `--config FILE` was given: with that flag it
-grades the file and never looks at the directory at all. Without it, an absent
-`config.db` is a failure naming the two ways to get one, exit 2.
+Default `/var/lib/nxdns`, overridable with `--data-dir DIR`. `nxdns run` and `nxdns import` create it and its parents at mode 0700 when it is missing; `nxdns check` and `nxdns export` do not create it. `export` fails if it is not there. `check` opens it only when no `--config FILE` was given: with that flag it grades the file and never looks at the directory at all. Without it, an absent `config.db` is a failure naming the two ways to get one, exit 2.
 
-`run`, `import` and `export` go through `DataDir.openConfigDb`, which opens
-`config.db` read/write, chmods it to 0600, enables WAL — creating
-`config.db-wal` and `config.db-shm` — and then runs any pending schema
-migrations. So `nxdns export` writes to the data directory, and on a database
-one schema version behind it migrates it. `export` also creates an empty
-`config.db` if the directory exists without one.
+`run`, `import` and `export` go through `DataDir.openConfigDb`, which opens `config.db` read/write, chmods it to 0600, enables WAL — creating `config.db-wal` and `config.db-shm` — and then runs any pending schema migrations. So `nxdns export` writes to the data directory, and on a database one schema version behind it migrates it. `export` also creates an empty `config.db` if the directory exists without one.
 
-`nxdns check` is the exception: it does not use that path at all. It opens
-`config.db` immutable, which is `SQLITE_OPEN_READONLY` plus `immutable=1`, so
-SQLite refuses every statement that would write and builds no wal-index. No
-`config.db-wal` and no `config.db-shm` appear beside the file, the mode is left
-alone, and no migration runs — a database behind this binary's schema is
-reported as a failure naming `nxdns run` as the fix. A `check` against a data
-directory leaves it byte-identical, and `check` reaches the database branch only
-when `config.db` is already there.
+`nxdns check` is the exception: it does not use that path at all. It opens `config.db` immutable, which is `SQLITE_OPEN_READONLY` plus `immutable=1`, so SQLite refuses every statement that would write and builds no wal-index. No `config.db-wal` and no `config.db-shm` appear beside the file, the mode is left alone, and no migration runs — a database behind this binary's schema is reported as a failure naming `nxdns run` as the fix. A `check` against a data directory leaves it byte-identical, and `check` reaches the database branch only when `config.db` is already there.
 
-`immutable=1` ignores any `-wal` file, so it is refused rather than used when
-one holds bytes: the newest settings would be invisible and `check` would grade
-older ones from the main file. That is the "uncheckpointed changes" failure in
-[the CLI reference](cli.md#what-check-does-not-do).
+`immutable=1` ignores any `-wal` file, so it is refused rather than used when one holds bytes: the newest settings would be invisible and `check` would grade older ones from the main file. That is the "uncheckpointed changes" failure in [the CLI reference](cli.md#what-check-does-not-do).
 
 | Path | What it is | Mode |
 | --- | --- | --- |
@@ -53,29 +30,15 @@ older ones from the main file. That is the "uncheckpointed changes" failure in
 
 ### The orphan sweep
 
-The sweep decides by id, not by suffix. It matches all seven names above and
-deletes those whose `<id>` is no longer a `blocklist_sources` row, so the
-compiled `.list`, `.wild` and `.allow` of a removed source go, and so do a
-`.raw.tmp`, `.list.tmp`, `.wild.tmp` or `.allow.tmp` left behind by a refresh
-that was killed before it could clean up. Files belonging to a source that still
-has a row are never touched, whatever state they are in: the sweep holds the same
-lock every refresh takes, so it never reads the directory while a refresh is
-part-way through.
+The sweep decides by id, not by suffix. It matches all seven names above and deletes those whose `<id>` is no longer a `blocklist_sources` row, so the compiled `.list`, `.wild` and `.allow` of a removed source go, and so do a `.raw.tmp`, `.list.tmp`, `.wild.tmp` or `.allow.tmp` left behind by a refresh that was killed before it could clean up. Files belonging to a source that still has a row are never touched, whatever state they are in: the sweep holds the same lock every refresh takes, so it never reads the directory while a refresh is part-way through.
 
 It runs at three moments:
 
-- at startup, before the first refresh pass — this is what collects what a
-  killed process left behind, and the compiled files of a source deleted while
-  the server was down;
-- before each scheduled update pass, ahead of the disk-space gate: the sweep
-  only unlinks, so it is the one step here that can give a critically full disk
-  room back, and gating it would keep the residue that helped fill the disk;
-- immediately after `DELETE /api/blocklists/{id}`, which is when an orphan is
-  actually created in normal operation. Without it a deleted list would keep its
-  megabytes until the next scheduled pass.
+- at startup, before the first refresh pass — this is what collects what a killed process left behind, and the compiled files of a source deleted while the server was down;
+- before each scheduled update pass, ahead of the disk-space gate: the sweep only unlinks, so it is the one step here that can give a critically full disk room back, and gating it would keep the residue that helped fill the disk;
+- immediately after `DELETE /api/blocklists/{id}`, which is when an orphan is actually created in normal operation. Without it a deleted list would keep its megabytes until the next scheduled pass.
 
-With `blocklist_update.enabled = false` there are no scheduled passes, so only
-the first and the last of those three happen.
+With `blocklist_update.enabled = false` there are no scheduled passes, so only the first and the last of those three happen.
 
 Each deletion is logged:
 
@@ -83,110 +46,48 @@ Each deletion is logged:
 info(blocklist_manager): pruned orphaned blocklist file 9999.list
 ```
 
-A failed sweep is a warning, not an outage — leftover bytes do not justify
-losing the refresh pass behind them, let alone the server.
+A failed sweep is a warning, not an outage — leftover bytes do not justify losing the refresh pass behind them, let alone the server.
 
-The temporaries of a source that still exists are cleaned by the refresh that
-owns them rather than by the sweep: each refresh deletes its own `.raw.tmp`,
-`.list.tmp`, `.wild.tmp` and `.allow.tmp` as it finishes, successfully or not.
+The temporaries of a source that still exists are cleaned by the refresh that owns them rather than by the sweep: each refresh deletes its own `.raw.tmp`, `.list.tmp`, `.wild.tmp` and `.allow.tmp` as it finishes, successfully or not.
 
-A `querylog.db` is moved aside when it is missing nothing but usability:
-SQLite reports it corrupt or not a database, `PRAGMA quick_check` does not
-answer `ok`, or its `user_version` fingerprint does not match the schema. Only
-the main file is renamed — its `-wal` and `-shm` are deleted, because a stale
-WAL would be replayed into the fresh database. A missing `querylog.db` is
-created without any aside file. The rename happens inside
-`querylog_schema.open`, before the 0600 chmod, and that chmod names
-`querylog.db` and its two sidecars only — so an aside file keeps the mode the
-file had at rename time, which for a `querylog.db` nxdns itself created is 0600
-and for one an operator put there is whatever they left it at. Nothing prunes
-the aside files; they accumulate until an operator removes them, and each one
-holds the same browsing history the live query log holds.
+A `querylog.db` is moved aside when it is missing nothing but usability: SQLite reports it corrupt or not a database, `PRAGMA quick_check` does not answer `ok`, or its `user_version` fingerprint does not match the schema. Only the main file is renamed — its `-wal` and `-shm` are deleted, because a stale WAL would be replayed into the fresh database. A missing `querylog.db` is created without any aside file. The rename happens inside `querylog_schema.open`, before the 0600 chmod, and that chmod names `querylog.db` and its two sidecars only — so an aside file keeps the mode the file had at rename time, which for a `querylog.db` nxdns itself created is 0600 and for one an operator put there is whatever they left it at. Nothing prunes the aside files; they accumulate until an operator removes them, and each one holds the same browsing history the live query log holds.
 
-The 0600 modes are not cosmetic. `config.db` holds the argon2id password hash
-and `querylog.db` holds the browsing history of every client on the LAN, so both
-are as sensitive as each other, and a WAL file holds the same rows as the
-database it belongs to. SQLite creates the main database at `0644 & ~umask`;
-nxdns chmods it to 0600 before enabling WAL, so the sidecars inherit 0600 rather
-than being created world-readable.
+The 0600 modes are not cosmetic. `config.db` holds the argon2id password hash and `querylog.db` holds the browsing history of every client on the LAN, so both are as sensitive as each other, and a WAL file holds the same rows as the database it belongs to. SQLite creates the main database at `0644 & ~umask`; nxdns chmods it to 0600 before enabling WAL, so the sidecars inherit 0600 rather than being created world-readable.
 
 ## The configuration file
 
-There is no default path. `--config FILE` names the file, and without that flag
-no file is read at all — a `config.zon` sitting in `/etc/nxdns` that no
-invocation names is inert. `/etc/nxdns/config.zon` is a convention the packaging
-follows, not a location nxdns probes.
+There is no default path. `--config FILE` names the file, and without that flag no file is read at all — a `config.zon` sitting in `/etc/nxdns` that no invocation names is inert. `/etc/nxdns/config.zon` is a convention the packaging follows, not a location nxdns probes.
 
-nxdns reads the file and never writes it, in either authority mode. It does not
-create the file or its directory either; the systemd unit's
-`ConfigurationDirectory=nxdns` creates `/etc/nxdns`, and the same unit's
-`ReadOnlyPaths=/etc/nxdns` denies the service write access to it, so the file
-cannot be modified by the process that reads it.
+nxdns reads the file and never writes it, in either authority mode. It does not create the file or its directory either; the systemd unit's `ConfigurationDirectory=nxdns` creates `/etc/nxdns`, and the same unit's `ReadOnlyPaths=/etc/nxdns` denies the service write access to it, so the file cannot be modified by the process that reads it.
 
-Under `run --config FILE` the file is the configuration and the database is the
-runtime substrate the server reads from: every start reconciles the one onto the
-other. So in that mode `config.db` is not the backup — the file is.
+Under `run --config FILE` the file is the configuration and the database is the runtime substrate the server reads from: every start reconciles the one onto the other. So in that mode `config.db` is not the backup — the file is.
 
-`nxdns export --out FILE` writes a ZON file at mode 0600 through a temporary
-file and a rename. That file carries `web.password_hash`, so treat exports as
-secrets. Without `--out` the export goes to stdout, where permissions are the
-redirect's business.
+`nxdns export --out FILE` writes a ZON file at mode 0600 through a temporary file and a rename. That file carries `web.password_hash`, so treat exports as secrets. Without `--out` the export goes to stdout, where permissions are the redirect's business.
 
 ## The log file
 
-Only when `logging.output = .file`. The path is `logging.file_path`, default
-`/var/log/nxdns/nxdns.log`, and validation requires it to be absolute.
+Only when `logging.output = .file`. The path is `logging.file_path`, default `/var/log/nxdns/nxdns.log`, and validation requires it to be absolute.
 
-**nxdns does not create the log directory.** It must exist and be writable by
-the user the service runs as before the process starts; under systemd the unit's
-`LogsDirectory=nxdns` does that.
+**nxdns does not create the log directory.** It must exist and be writable by the user the service runs as before the process starts; under systemd the unit's `LogsDirectory=nxdns` does that.
 
-Rotation triggers at `logging.max_size_mb` MiB and keeps `logging.max_files`
-files in total, the live one included, so the highest generation on disk is
-`logging.max_files - 1`. With the default 5 that is `nxdns.log` plus `nxdns.log.1`
-through `nxdns.log.4`. Rotation deletes the highest generation, renames each
-remaining one up by one, then renames the live file to `.1`. A `max_files` of 1
-or 0 deletes the live file instead of renaming it. The directory holding the log
-file is also sampled by the disk monitor.
+Rotation triggers at `logging.max_size_mb` MiB and keeps `logging.max_files` files in total, the live one included, so the highest generation on disk is `logging.max_files - 1`. With the default 5 that is `nxdns.log` plus `nxdns.log.1` through `nxdns.log.4`. Rotation deletes the highest generation, renames each remaining one up by one, then renames the live file to `.1`. A `max_files` of 1 or 0 deletes the live file instead of renaming it. The directory holding the log file is also sampled by the disk monitor.
 
 | Path | What it is | Mode |
 | --- | --- | --- |
 | `logging.file_path` (default `/var/log/nxdns/nxdns.log`) | The live process log. Opened write-only and written at a tracked offset; created when it does not exist. | `0666 & ~umask` — nxdns never chmods it |
 | `<file_path>.1` … `<file_path>.<max_files - 1>` | Rotated generations, newest first. | Inherited from the live file they were renamed from |
 
-**Do not point external logrotate at this file.** nxdns owns the rotation of
-its own log. There is no append mode in Zig 0.16, so the writer reads the file
-length once when it opens the file and then writes every line at an offset it
-tracks in the process. A rotator that moves the file behind it breaks that
-offset, and nxdns does not notice until the next restart:
+**Do not point external logrotate at this file.** nxdns owns the rotation of its own log. There is no append mode in Zig 0.16, so the writer reads the file length once when it opens the file and then writes every line at an offset it tracks in the process. A rotator that moves the file behind it breaks that offset, and nxdns does not notice until the next restart:
 
-- With `copytruncate` the offset survives the truncation, so the next line
-  lands where it would have without it. The file regrows with a sparse,
-  NUL-filled prefix as long as the log that was just rotated away.
-- With rename-and-create nxdns keeps writing to the renamed inode. The new
-  file stays empty, the renamed one grows without bound, and
-  `logging.max_size_mb` bounds nothing on disk.
+- With `copytruncate` the offset survives the truncation, so the next line lands where it would have without it. The file regrows with a sparse, NUL-filled prefix as long as the log that was just rotated away.
+- With rename-and-create nxdns keeps writing to the renamed inode. The new file stays empty, the renamed one grows without bound, and `logging.max_size_mb` bounds nothing on disk.
 
-If an external rotator has to own the file, set `logging.output = .stderr` and
-let the collector capture the stream instead.
+If an external rotator has to own the file, set `logging.output = .stderr` and let the collector capture the stream instead.
 
-The log file is the one path here nxdns does not set a mode on. `config.db` and
-`querylog.db` are chmodded to 0600 whatever the umask; the log file is left at
-whatever the umask gives it. Under the shipped unit that is 0600, because
-`deploy/systemd/nxdns.service` sets `UMask=0077`. Run from a shell with the
-usual `umask 022` it is 0644, and `LogsDirectory=nxdns` leaves the directory at
-systemd's default 0755, so a log written there is readable by any local user.
+The log file is the one path here nxdns does not set a mode on. `config.db` and `querylog.db` are chmodded to 0600 whatever the umask; the log file is left at whatever the umask gives it. Under the shipped unit that is 0600, because `deploy/systemd/nxdns.service` sets `UMask=0077`. Run from a shell with the usual `umask 022` it is 0644, and `LogsDirectory=nxdns` leaves the directory at systemd's default 0755, so a log written there is readable by any local user.
 
-With `logging.output = .stderr` or `.syslog` nxdns writes to stderr and creates
-no file; under systemd the journal captures it.
+With `logging.output = .stderr` or `.syslog` nxdns writes to stderr and creates no file; under systemd the journal captures it.
 
 ## Certificate and key files
 
-`doh_server.cert_path` / `key_path` and `dot_server.cert_path` / `key_path`,
-conventionally under `/etc/nxdns`. nxdns reads them, never writes or creates
-them. Both must be readable by the user nxdns runs as, and the key must belong
-to the certificate: `nxdns check` loads the pair and fails when it does not. The
-key should also be readable by its owner only, which `check` warns about when it
-is not. A
-watcher polls both files and swaps a renewed pair in without a restart. See
-[enable DoH and DoT](../how-to/enable-doh-and-dot.md).
+`doh_server.cert_path` / `key_path` and `dot_server.cert_path` / `key_path`, conventionally under `/etc/nxdns`. nxdns reads them, never writes or creates them. Both must be readable by the user nxdns runs as, and the key must belong to the certificate: `nxdns check` loads the pair and fails when it does not. The key should also be readable by its owner only, which `check` warns about when it is not. A watcher polls both files and swaps a renewed pair in without a restart. See [enable DoH and DoT](../how-to/enable-doh-and-dot.md).