feat(wiki): add installation / troubleshooting / contributing how-to scopes

The 15-scope catalogue covered explanation (architecture, services,
data-flow), reference (api, commands, tools, mcp, ci-cd), and one
tutorial (onboarding) — but the Diátaxis how-to quadrant was empty.
Users with a concrete goal (install on a fresh box, fix a known
error, land their first PR) had no canonical landing page.

Three new universal scopes:

* ``installation`` — install + configuration walk-through, OS by OS,
  every env var named with its default, post-install verification
  commands. Anchor filenames: install / installation /
  configuration. Suggested kind: how-to.
* ``troubleshooting`` — symptom → diagnosis → fix table for every
  known issue and common error. Sourced from runbook incidents
  + ADR consequences + lessons. Anchor filenames: troubleshooting /
  known-issues / faq / common-errors. Suggested kind: how-to.
* ``contributing`` — fork/branch policy, test commands, lint rules,
  commit convention, PR review expectations. Distinct from onboarding
  (which is day-one setup); this is the edit-to-merge path. Anchor
  filenames: contributing / CONTRIBUTING / contribute / development.
  Suggested kind: how-to.

Total canonical scopes: 15 → 18. cortex coverage drops from 15/15
to 15/18 until the autonomous worker authors the new anchors on the
next cycle; every other project's coverage gap grows by 3 likewise
and the worker drains them in priority order.

121 wiki tests + ruff format + ruff check all green.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

Author: cdeust

mcp_server/core/wiki_coverage.py

@@ -340,6 +340,74 @@ class Scope:
         directories=("guides", "tutorial"),
         suggested_kind="tutorial",
     ),
+    # ── Task-oriented how-to guides (Diátaxis: how-to quadrant) ────────
+    #
+    # Onboarding above and code-walkthrough cover the learning + reading
+    # axes; what's missing is the *task-oriented* how-to layer — the
+    # guides a user hits when they have a concrete goal already
+    # (install, fix a known error, contribute). Three universal
+    # categories cover the bulk of project-level user demand:
+    Scope(
+        name="installation",
+        title="Installation & configuration",
+        description=(
+            "Step-by-step install + configuration walk-through, OS by OS, "
+            "with every environment variable named and its default. Beyond "
+            "onboarding (which is the day-one path) this is the reference "
+            "for every configuration knob, every install variant (CLI, "
+            "Docker, source clone, plugin marketplace), and the post-"
+            "install verification commands. Include screenshots / sample "
+            "configs where useful."
+        ),
+        anchor_filenames=(
+            "installation.md",
+            "install.md",
+            "configuration.md",
+            "configure.md",
+        ),
+        directories=("guides", "how-to"),
+        suggested_kind="how-to",
+    ),
+    Scope(
+        name="troubleshooting",
+        title="Troubleshooting & known issues",
+        description=(
+            "Symptom → diagnosis → fix table for every known issue, "
+            "common error message, and pitfall. Each entry: the exact "
+            "log line or symptom, root cause, recovery steps, prevention. "
+            "Sourced from runbook incidents + ADR consequences + lessons "
+            "captured in memory. The page a user opens when something "
+            "breaks at 3am."
+        ),
+        anchor_filenames=(
+            "troubleshooting.md",
+            "known-issues.md",
+            "faq.md",
+            "common-errors.md",
+        ),
+        directories=("guides", "how-to", "runbook"),
+        suggested_kind="how-to",
+    ),
+    Scope(
+        name="contributing",
+        title="Contributing guide",
+        description=(
+            "How to land a change in this project: fork / branch policy, "
+            "test commands, lint rules, commit-message convention, PR "
+            "template, code-review expectations, who reviews what, how "
+            "long things typically take. Distinct from onboarding "
+            "(reader is already set up); this is the path from edit to "
+            "merge."
+        ),
+        anchor_filenames=(
+            "contributing.md",
+            "CONTRIBUTING.md",
+            "contribute.md",
+            "development.md",
+        ),
+        directories=("guides", "how-to"),
+        suggested_kind="how-to",
+    ),
 )