docs: move docs to RunicGateway/docs, repoint all references

Extracted docs/ (ADMIN_CONTROLS, INTEGRATION, PLAN, PROTOCOL_2, RESEARCH,
SHARD_PREREQS) into the central RunicGateway/docs repo under link/, with
full commit history preserved via git filter-repo.

The source cites these design docs by section throughout, so every in-repo
reference (C# + Rust comments, Bridge.cfg, and the READMEs) is repointed at
the new docs-repo URL. README references are rendered as markdown links; a
Documentation pointer section is added to the top-level README.

Docs repo: https://gitea.whitlocktech.com/RunicGateway/docs

overlay/Scripts/Custom/Bridge/BridgeProfile.cs

@@ -15,7 +15,7 @@ namespace Server.Custom.Bridge
     ///
     ///     A profile is the single most expensive read in the bridge (~0.07 ms + ~2.4 KB at the
     ///     seeded scale, more for a fully-kitted character), so it is built on demand only, never in
-    ///     a sweep. See docs/PLAN.md §1.
+    ///     a sweep. See https://gitea.whitlocktech.com/RunicGateway/docs/src/branch/main/link/PLAN.md §1.
     /// </summary>
     public static class BridgeProfile
     {
@@ -83,7 +83,7 @@ namespace Server.Custom.Bridge
             }
             sb.Append(']');
 
-            // worn equipment only — not the backpack/bank (see docs/PLAN.md §IV.4)
+            // worn equipment only — not the backpack/bank (see https://gitea.whitlocktech.com/RunicGateway/docs/src/branch/main/link/PLAN.md §IV.4)
             sb.Append(",\"equipment\":[");
             first = true;
             foreach (var item in m.Items)
@@ -104,7 +104,7 @@ namespace Server.Custom.Bridge
         }
 
         /// <summary>
-        ///     The titles a character holds (docs/PROTOCOL_2.md §10.3). `selected` is the index into
+        ///     The titles a character holds (https://gitea.whitlocktech.com/RunicGateway/docs/src/branch/main/link/PROTOCOL_2.md §10.3). `selected` is the index into
         ///     `reward` currently displayed (-1 if none). `fameKarma` and `skill` are the computed
         ///     display titles (may be absent). `reward` is the raw reward-title list — an entry may be
         ///     a cliloc number (as a string) or a literal string; resolve clilocs website-side.