chore(android): scaffold Gossamer Android shell (#83 sub-PR #3)

[hyperpolymath]

Sub-PR #3 of the Android Kotlin→Rust/Gossamer migration epic (#83, RFC PR #97, tracking sub-issue #109). Scaffolding only. No behaviour change to existing crates; the legacy Kotlin android/app/ tree is untouched.

Files added (all under android/gossamer/, all SPDX-License-Identifier: MPL-2.0)

File	Purpose
gossamer.conf.json	Gossamer app config (analogous to tauri.conf.json). Schema mirrored from hyperpolymath/gossamer and hyperpolymath/panll. Carries identity ai.neurophone, the bundle.mobile.android block (minSdk 26 / targetSdk 34 + the permission set from the legacy AndroidManifest.xml), dev/build runner config.
app/src/main/java/ai/neurophone/NeurophoneMainActivity.java	Java shim extending io.gossamer.GossamerActivity; overrides getInitialHtml() to load placeholder HTML in the Gossamer WebView.
Cargo.toml	Standalone (non-workspace) scaffold manifest for the future neurophone-gossamer cdylib. gossamer-rs dep commented out (see below).
src/lib.rs	Inert placeholder lib so the standalone crate compiles; documents wiring TODOs.
README.adoc	Documents resolvability, GossamerActivity API assumptions, TODOs/risks for #4–#8.
Cargo.lock	Lock for the standalone scaffold crate (pins serde/serde_json placeholder deps).

The android/** subtree is exempt from the banned-language CI gate via .hypatia-baseline.json on main, so the hand-written Java shim is acceptable here.

gossamer-rs resolvability outcome

gossamer-rs v0.1.0 is NOT published to crates.io. In the estate it is consumed as a path dependency from the sibling hyperpolymath/gossamer repo at bindings/rust — precedent from hyperpolymath/panll:

gossamer-rs = { path = "../gossamer/bindings/rust" }

That sibling checkout doesn't exist in a neurophone clone, so wiring it as a hard dependency would break the build. Per the hard constraint (CI green > "complete" dep), it is left commented out with TODO(#83 sub-PR #8). The scaffold manifest is also kept out of the root workspace members and carries an empty [workspace] table, so neither cargo build --workspace nor cargo test --workspace ever touches it.

What I verified (build/test)

• cargo metadata --no-deps for the root workspace → the 8 existing crates only; neurophone-gossamer is not a member. My additions are inert to the workspace.
• Standalone scaffold: cargo test --manifest-path android/gossamer/Cargo.toml → compiles + 1 test passes.
• cargo build --workspace / cargo test --workspace fail only in crates/esn and crates/lsm (ndarray-rand 0.16 vs rand 0.10 API skew: random/sample/random_using). This failure pre-exists on main — reproduced in a pristine main worktree (cargo build -p esn exits 101 on 0a88e45). My PR neither introduces nor worsens it. ⚠️ Pre-existing red workspace flagged below.

GossamerActivity API assumptions (read from hyperpolymath/gossamer android/src/main/java/io/gossamer/)

• io.gossamer.GossamerActivity extends android.app.Activity.
• Loads libgossamer.so via System.loadLibrary("gossamer") in a static block.
• onCreate() builds a full-screen WebView, enables JS + DOM storage, disables file:///content access, registers the GossamerBridge JS interface (window.GossamerBridge.postMessage(json)), and calls native nativeInit(activity, webview).
• Content via overriding getInitialHtml() (HTML String) or getInitialUrl() (URL String); getInitialHtml() takes precedence — we override it.
• Gossamer on Android is webview-only today.
• Assumed: the gossamer Android sources + libgossamer.so are vendored/linked into the app module at build time (sub-PR chore(deps): bump the actions group with 9 updates #8), so io.gossamer.GossamerActivity is on the classpath. The shim is therefore not part of any CI build step yet.

TODOs / risks for sub-PRs #4–#8

• chore(deps): update thiserror requirement from 1.0 to 2.0 #4 — Port NativeLib: map the 11 JNI methods (init/start/stop/processSensor/queryLocal/queryClaude/query/getNeuralContext/getState/reset/isRunning) to Gossamer IPC command handlers calling the Rust core (crates/neurophone-core, crates/neurophone-android). IPC name/payload contract is undefined.
• chore(deps): update ndarray requirement from 0.15 to 0.17 #5 — Port NeurophoneService foreground sensor loop.
• chore(deps): update reqwest requirement from 0.11 to 0.12 #6 — Port BootReceiver.
• chore(deps): update rand requirement from 0.8 to 0.9 #7 — Port the home-screen widgets.
• chore(deps): bump the actions group with 9 updates #8 — Real frontend bundle (frontendDist) + full IPC wiring; enable gossamer-rs (resolve the sibling-checkout/build-integration question); decide gossamer CLI vs Gradle for the APK build; then remove the legacy Kotlin android/app/ tree.
• Licensing risk: gossamer-rs is AGPL-3.0-or-later; everything added here is MPL-2.0. Whether the cdylib linking gossamer-rs can stay MPL-2.0 or must adopt a compatible license is an open question to resolve before chore(deps): bump the actions group with 9 updates #8.

Refs #83, #97, #109.

https://claude.ai/code/session_01Gu1JFCZHuBtBhAWPr4sMQw

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