docs: define initial ghidra-cli product

CONTEXT.md

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+# Headless Reverse Engineering
+
+This context describes how users ask reproducible, read-only questions about
+binaries through Ghidra without managing Ghidra's internal project model.
+
+## Language
+
+**Sample**:
+An immutable sequence of input bytes identified by a cryptographic content
+digest. Identical bytes are the same Sample even when they have different file
+names or locations.
+_Avoid_: Binary, file, target
+
+**Analysis Profile**:
+The declared analysis inputs other than the Sample, including the Ghidra
+version, analyzer configuration, language selection, and tool protocol version.
+_Avoid_: Configuration, settings
+
+**Analysis**:
+The reusable body of facts Ghidra derives from one Sample under one Analysis
+Profile.
+_Avoid_: Project, database, workspace
+
+**Query**:
+A read-only question evaluated against an Analysis. A Query cannot change the
+Sample or Analysis.
+_Avoid_: Command, job, operation
+
+**Function Selector**:
+An unambiguous reference used to choose a function by address or resolved
+symbol name.
+_Avoid_: Function name, function ID
+
+**Artifact**:
+A durable, schema-versioned representation of a Query result tied to its
+Analysis.
+_Avoid_: Output, report, result file
+
+**Analysis Store**:
+The tool-owned collection of reusable Analyses and Artifacts. It is disposable
+and never contains the authoritative Sample.
+_Avoid_: Project directory, cache directory, workspace
+