chore: update project state and prepare for image support development

- Add comprehensive image test document with various image types
- Update project structure with development artifacts
- Prepare foundation for image support enhancement phase
- Include test files for validating image editing workflows

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude <noreply@anthropic.com>

node_modules/istanbul-lib-instrument/src/source-coverage.js

@@ -0,0 +1,135 @@
+const { classes } = require('istanbul-lib-coverage');
+
+function cloneLocation(loc) {
+    return {
+        start: {
+            line: loc && loc.start.line,
+            column: loc && loc.start.column
+        },
+        end: {
+            line: loc && loc.end.line,
+            column: loc && loc.end.column
+        }
+    };
+}
+/**
+ * SourceCoverage provides mutation methods to manipulate the structure of
+ * a file coverage object. Used by the instrumenter to create a full coverage
+ * object for a file incrementally.
+ *
+ * @private
+ * @param pathOrObj {String|Object} - see the argument for {@link FileCoverage}
+ * @extends FileCoverage
+ * @constructor
+ */
+class SourceCoverage extends classes.FileCoverage {
+    constructor(pathOrObj) {
+        super(pathOrObj);
+        this.meta = {
+            last: {
+                s: 0,
+                f: 0,
+                b: 0
+            }
+        };
+    }
+
+    newStatement(loc) {
+        const s = this.meta.last.s;
+        this.data.statementMap[s] = cloneLocation(loc);
+        this.data.s[s] = 0;
+        this.meta.last.s += 1;
+        return s;
+    }
+
+    newFunction(name, decl, loc) {
+        const f = this.meta.last.f;
+        name = name || '(anonymous_' + f + ')';
+        this.data.fnMap[f] = {
+            name,
+            decl: cloneLocation(decl),
+            loc: cloneLocation(loc),
+            // DEPRECATED: some legacy reports require this info.
+            line: loc && loc.start.line
+        };
+        this.data.f[f] = 0;
+        this.meta.last.f += 1;
+        return f;
+    }
+
+    newBranch(type, loc, isReportLogic = false) {
+        const b = this.meta.last.b;
+        this.data.b[b] = [];
+        this.data.branchMap[b] = {
+            loc: cloneLocation(loc),
+            type,
+            locations: [],
+            // DEPRECATED: some legacy reports require this info.
+            line: loc && loc.start.line
+        };
+        this.meta.last.b += 1;
+        this.maybeNewBranchTrue(type, b, isReportLogic);
+        return b;
+    }
+
+    maybeNewBranchTrue(type, name, isReportLogic) {
+        if (!isReportLogic) {
+            return;
+        }
+        if (type !== 'binary-expr') {
+            return;
+        }
+        this.data.bT = this.data.bT || {};
+        this.data.bT[name] = [];
+    }
+
+    addBranchPath(name, location) {
+        const bMeta = this.data.branchMap[name];
+        const counts = this.data.b[name];
+
+        /* istanbul ignore if: paranoid check */
+        if (!bMeta) {
+            throw new Error('Invalid branch ' + name);
+        }
+        bMeta.locations.push(cloneLocation(location));
+        counts.push(0);
+        this.maybeAddBranchTrue(name);
+        return counts.length - 1;
+    }
+
+    maybeAddBranchTrue(name) {
+        if (!this.data.bT) {
+            return;
+        }
+        const countsTrue = this.data.bT[name];
+        if (!countsTrue) {
+            return;
+        }
+        countsTrue.push(0);
+    }
+
+    /**
+     * Assigns an input source map to the coverage that can be used
+     * to remap the coverage output to the original source
+     * @param sourceMap {object} the source map
+     */
+    inputSourceMap(sourceMap) {
+        this.data.inputSourceMap = sourceMap;
+    }
+
+    freeze() {
+        // prune empty branches
+        const map = this.data.branchMap;
+        const branches = this.data.b;
+        const branchesT = this.data.bT || {};
+        Object.keys(map).forEach(b => {
+            if (map[b].locations.length === 0) {
+                delete map[b];
+                delete branches[b];
+                delete branchesT[b];
+            }
+        });
+    }
+}
+
+module.exports = { SourceCoverage };