#600 Local source-loading should discover a report co-located with its model in a paths.base:manifest extension

Problem

A report is, in MVC terms, the view for a model — it naturally belongs in the same extension as the model it summarizes. Publishing supports that (the manifest reports: field bundles the report alongside the model). Local source development does not.

In a self-contained extension using paths.base: manifest — manifest, model, README, LICENSE all in one directory under extensions/models/<name>/ — a report listed in reports: and placed in that same directory:

• bundles and loads correctly once pulled, but
• is NOT discovered during local source development: the model loads (it matches the extensions/models/** discovery glob) while the co-located report does not (report discovery only globs extensions/reports/**).

So the extension loads partially from source (model yes, report no) even though it loads fully when pulled — a dev/prod parity gap. And the manifest can't point at extensions/reports/ instead, because manifest paths reject .. ("Path must be relative and must not contain '..' components").

Reproduce

1. extensions/models/myext/ with manifest.yaml (paths.base: manifest), a model .ts, and a report .ts listed under reports:.
2. swamp doctor extensions --verbose — the model registers; the report does not (no report row for it).
3. A method whose definition has reports.require: [<that report>] does not run it locally.
4. swamp extension source add <that dir> does not help — a path already covered by the repo-root layout is ignored to prevent double-loading.

(Confirmed by dropping .swamp/_extension_catalog.db and rescanning — the report never registers from the model dir.)

Proposed

Local source-loading should honor a discovered manifest's declared files — load all declared components (models, reports, vaults, drivers, …) from the manifest's own directory — so source/dev loading matches the published bundle. (Alternatively, the per-type discovery globs could include paths.base: manifest extension subdirectories.)

Impact / workaround

Today, a bundled report can't be exercised from source. The workarounds are to keep the report in extensions/reports/ (separated from the extension it ships in) or publish it as a standalone companion extension — both of which defeat the "view ships with its model" layout the manifest otherwise supports.