feat(wallet): add configurable min_output_value filter

[noahjoeris]

Description

Adds a runtime-only min_output_value: Option<Amount> setting to Wallet that filters outputs below a chosen threshold across wallet queries and coin selection. Useful for applications that want to ignore dust/spam outputs without reimplementing BDK's internal logic.

Closes #375

Affected methods: balance, list_unspent, list_output, sent_and_received, net_value, tx_details, and coin selection. get_utxo and fee calculations are intentionally not filtered.

Notes to the reviewers

• Named min_output_value rather than dust_threshold to avoid confusion with the existing coin selection dust_threshold and Bitcoin's relay dust policy.
• Not persisted; treated as a runtime filter applied on top of stored wallet state. It can be provided when creating/loading via CreateParams::min_output_value() / LoadParams::min_output_value(), or changed at runtime via Wallet::set_min_output_value()
• Filtering is applied in bdk_wallet, not pushed down into bdk_chain. The trade-off is that some methods are no longer thin wrappers around bdk_chain. This can be refactored downstream if desired.
• Happy to discuss any of these decisions and update if necessary.

Changelog notice

• Added runtime min_output_value support to Wallet, CreateParams, and LoadParams
• Added Wallet::net_value
• balance, list_unspent, list_output, sent_and_received, net_value, and coin selection now honor min_output_value

Checklists

All Submissions:

• I've signed all my commits
• I followed the contribution guidelines
• I ran just p before pushing

New Features:

• I've added tests for the new feature
• I've added docs for the new feature

[codecov]

Codecov Report

❌ Patch coverage is 98.43750% with 1 line in your changes missing coverage. Please review.
✅ Project coverage is 80.29%. Comparing base (4e202c8) to head (d7e147b).
⚠️ Report is 8 commits behind head on master.

Files with missing lines	Patch %	Lines
src/wallet/mod.rs	98.07%	0 Missing and 1 partial ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##           master     #427      +/-   ##
==========================================
+ Coverage   80.04%   80.29%   +0.25%     
==========================================
  Files          24       24              
  Lines        5336     5395      +59     
  Branches      242      245       +3     
==========================================
+ Hits         4271     4332      +61     
+ Misses        987      984       -3     
- Partials       78       79       +1     

Flag	Coverage Δ
rust	80.29% <98.43%> (+0.25%)	⬆️

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[Dmenec]

Concept ACK. Related with the sent_and_received / net_value approach, why apply min_output_value to transaction accounting methods? A tx already broadcast moved exactly what it moved on-chain. I'd expect the threshold to act as an operational filter for UTXO management, but not change how historical transactions are reported. Maybe I'm ignoring some use case...

Also, #431 rewrites balance() for trusted/untrusted pending classification, worth a look as both touch the same function.