drop sfnetworks

[atsyplenkov]

1. feat: add GEOS/igraph skeleton graph layer
   R/skeleton_graph.R (new — builder + 6 primitives)
   tests/testthat/test-skeleton_graph.R (new — 10 tests / 40 expectations)

2. refactor(cnt_path): route on skeleton graph instead of sfnetworks
   R/cnt_path.R (methods + master + roxygen)
   man/cnt_path.Rd (regenerated details)
   tests/testthat/test-cnt_path.R (baseline migration test)

3. refactor(cnt_path_guess): route on skeleton graph instead of sfnetworks
   R/cnt_path_guess.R (master)
   R/utils.R (find_closest_nodes -> graph primitive)
   tests/testthat/test-cnt_path_guess.R (baseline migration test)

4. refactor(cnt_skeleton): build anchor topology on skeleton graph
   R/cnt_skeleton_anchors.R (raw + cleaned analysis graphs)
   tests/testthat/test-cnt_skeleton.R (helper rename, neighbor calls, baseline test)

5. chore: drop sfnetworks dependency
   DESCRIPTION (remove Imports line)
   codemeta.json (remove req, renumber, add igraph)
   NEWS.md (UPDATES note)

[netlify]

❌ Deploy Preview for centerline failed. Why did it fail? →

Name	Link
🔨 Latest commit	aadd6c7
🔍 Latest deploy log	https://app.netlify.com/projects/centerline/deploys/6a5a4d835fd2700008991617

[codecov-commenter]

⚠️ Please install the to ensure uploads and comments are reliably processed by Codecov.

Codecov Report

❌ Patch coverage is 96.63866% with 8 lines in your changes missing coverage. Please review.
✅ Project coverage is 85.53%. Comparing base (73875f0) to head (aadd6c7).

Files with missing lines	Patch %	Lines
R/skeleton_graph.R	94.53%	7 Missing ⚠️
R/cnt_skeleton_anchors.R	98.11%	1 Missing ⚠️
❗ Your organization needs to install the Codecov GitHub app to enable full functionality.

Additional details and impacted files

@@            Coverage Diff             @@
##           master      #24      +/-   ##
==========================================
+ Coverage   85.43%   85.53%   +0.10%     
==========================================
  Files           8        9       +1     
  Lines        1558     1625      +67     
==========================================
+ Hits         1331     1390      +59     
- Misses        227      235       +8     

☔ View full report in Codecov by Harness.
📢 Have feedback on the report? Share it here.

🚀 New features to boost your workflow:

• ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.