cmap route hard fails when generated route stats JSON is corrupted

[GYF0311]

Summary

cmap route hard fails when .context/generated/stats/route-usage.json exists but contains malformed JSON. This generated stats file should not block routing; route should warn and skip/rebuild the stats file, or recover by starting from empty stats.

Repro

In /Users/gaoyifan/code/lorekit:

cmap version
# 0.2.2

cmap route "docs install skills"

Observed output:

Unexpected non-whitespace character after JSON at position 8182 (line 343 column 1)

The same cmap route "docs install skills" succeeds in /Users/gaoyifan/Desktop/CMAP_coding, so the command itself is installed and runnable.

Evidence

/opt/homebrew/bin/cmap resolves to the local CMAP checkout:

/opt/homebrew/bin/cmap -> ../lib/node_modules/cmap/dist/cli.js
npm ls -g cmap --depth=0 -> cmap@0.2.2 -> /Users/gaoyifan/Desktop/CMAP_coding

The failing generated file in the lorekit repo is:

.context/generated/stats/route-usage.json

JSON validation shows only this generated stats file is invalid; graph JSON files parse correctly:

BAD .context/generated/stats/route-usage.json Unexpected non-whitespace character after JSON at position 8182 (line 343 column 1)
OK .context/graph/edges.json
OK .context/graph/files.json
OK .context/graph/graph.meta.json
OK .context/graph/modules.json

The malformed tail starts at line 343:

342 }
343 intenance",
344         "docs-tests-release"
345       ]
346     }
347   ]
348 }

Expected

Because .context/generated/stats/route-usage.json is generated / auxiliary state, cmap route should still produce the route result. It can:

• warn and skip stats update,
• rewrite stats from an empty default,
• move the malformed stats file aside through a recoverable mechanism,
• or provide a clear repair command.

But it should not prevent route selection from reading .context/MAP.md and .context/modules/*.md.

Suspected code path

runRoute() calls recordRouteUsage() after routeTask() succeeds. recordRouteUsage() reads .context/generated/stats/route-usage.json through readRouteUsageStats(), which currently does a direct JSON.parse(await readFile(...)) without malformed-file recovery.

Relevant source:

• src/commands/route.ts
• src/core/generated-stats.ts

Impact

This breaks the primary CMAP handoff workflow in repos where route stats become corrupted, even though canonical context files and cmap verify --changed can still be healthy.

Verification context

In /Users/gaoyifan/code/lorekit, these still pass:

cmap verify --changed
cmap obsidian export --check --out _cmap/lorekit
cmap view export --check --ui-lang zh-CN --out _cmap-view

So the issue is not canonical context structure; it is route's dependency on generated stats parseability.