docs(okf): 53 Obsidian wikilinks become OKF links

`[[page|Label]]` is Obsidian syntax, not OKF. `kb-lint` resolves it Obsidian-style — by
filename, anywhere in the bundle — so it has never tripped the link gate, while every other
consumer of the bundle (an OKF renderer, a Gitea wiki export, `grep` for reachability) sees
bracketed text where a link should be. That is how two generated pages ended up with no
inbound link at all and nobody noticed: the my-first link census of the bundle reported them
as orphans because their only inbound edges were wikilinks.

Mechanical conversion, 52 links across 17 pages, each resolved against the same page set
`kb-lint` uses: an explicit `|Label` is kept verbatim, an unlabelled link takes the target's
frontmatter `title`. Targets are emitted bundle-absolute (`/tools/niri/tips.md`), the form
the spec recommends and the form 99 existing links in this bundle already use.

Two links were `[[index]]`, which resolves by filename to 21 pages — the ambiguity that
filename-resolution invites. Both meant their own directory's index, so both are now written
out in full: `/tools/gitea/index.md`, `/tools/niri/index.md`.

The linter still tolerates wikilinks; whether it should reject them outright is an open
question on #64, because that would replace the two tests pinning today's tolerance.

Refs #64

omp-docs/tools/niri/displays.md

@@ -178,17 +178,17 @@ The `environment { render-node "/dev/dri/renderD129" }` pin found in the
 hybrid; pin kept the iGPU as display owner and sidesteps the suspend/resume
 deadlock documented in the sleep-wake investigation). Deploying that base
 file on blankpad pins a render node that does not exist — this is why
-blankpad runs the `zz-blankpad` override layer (see [[index|the per-host
-symlink matrix]]).
+blankpad runs the `zz-blankpad` override layer (see [the per-host symlink
+matrix](/tools/niri/index.md)).
 
 ## Reload
 
 `niri msg action load-config-file` reloads live. Never `SIGHUP` the process
-— see [[tips]].
+— see [Niri Tips and Gotchas](/tools/niri/tips.md).
 
 ## See Also
 
 - [Niri](/tools/niri/index.md) — compositor overview and config layout
-- [[tips|tips]] — reload path, `niri msg layers/casts`, includes
-- [[noctalia-shell|noctalia-shell]] — notification shown on desk switch
-- [[cachyos|cachyos]] — operating system
+- [tips](/tools/niri/tips.md) — reload path, `niri msg layers/casts`, includes
+- [noctalia-shell](/tools/noctalia-shell.md) — notification shown on desk switch
+- [cachyos](/tools/cachyos.md) — operating system